Recent itsdavis_ncst_reports items

Review and Analysis of Current and Future Battery Technologies for Heavy Duty Electric Vehicles

Wed, 17 Sep 2025 00:00:00 +0000

The transportation sector contributes significantly to emissions, with heavy-duty (HD) vehicles responsible for a disproportionately large share. Zero-emission trucks, particularly battery electric trucks (BETs), have emerged as potential solutions to reduce these emissions. BETs offer benefits such as high energy efficiency with low operating noise while facing the challenges such as range anxiety and inadequate infrastructure. This report presents a survey of the latest advancements in battery technologies and primarily focusing on Class 7 and Class 8 heavy-duty vehicles due to their critical role in freight transport. This report further provides information of the status and future expectations of BETs. Finally, a feasibility analysis is presented to assess the battery requirement and operating cost for a 410-mile route from Long Beach, CA to San Francisco, CA. The results highlight the importance of charging scheduling and strategic planning for infrastructure to lower...

Understanding Real-World Brake Activity: A Key to Assessing Non-Tailpipe Emission Sources

Wed, 17 Sep 2025 00:00:00 +0000

Understanding and mitigating non-tailpipe emissions, particularly those from braking activities, is crucial for improving air quality and public health. This study investigates the impact of vehicle brake activity on mobile-source particulate matter (PM) emissions at signalized intersections using a multi-modal data collection approach. The research integrates LiDAR-based trajectory detection, roadside camera monitoring, drone surveillance, and in-vehicle sensor data to analyze braking behaviors and their associated emissions. A hybrid physical-machine learning model was developed to detect braking events and estimate brake-induced PM emissions. The methodology involves LiDAR-based vehicle tracking, trajectory refinement, brake activity detection, and brake emission estimation. By leveraging deep learning algorithms for multi-object tracking and data fusion techniques, the study provides a robust framework for real-time brake activity monitoring. The study further incorporates...

Youth Cruz Free: Fare Free Bus and Ridership Behavior among Santa Cruz County Teens

Wed, 17 Sep 2025 00:00:00 +0000

Since the beginning of the twenty-first century, young people have become a considerable share of public transit users. However, younger representatives of this age group still face many barriers to access transit infrastructure and benefit from its service. This study examines a Youth Cruz Free program launched by the Santa Cruz METRO in March 2023, allowing kids and teenagers of school age to use the service for free. The researchers were interested in understanding how the program has changed the travel behavior of teenagers, whether it encourages adolescents to use the service after they turn 18, and what factors influence their overall ridership of Santa Cruz METRO. To reach both current high school students and recent graduates, the researchers completed two rounds of surveys distributed among high schools in Santa Cruz County. The surveys asked about adolescents’ sociodemographics, the availability of different modes of transportation, school attendance, and other variables...

Consumer Resistance to Electric Vehicles: Getting to 100 Percent Zero Emission New Car Sales

Wed, 17 Sep 2025 00:00:00 +0000

Meeting and sustaining a requirement that 100 percent of new passenger vehicle and light-duty truck sales be zero emission vehicles (ZEVs) requires everyone who acquires a new vehicle to only acquire ZEVs. This puts an onus on understanding resistance to ZEVs: who is resistant and why. These questions are addressed using survey data from repeated cross-sectional samples of all-car buying households in California in the years 2017, 2019, and 2021. Concepts of resistance are introduced and provisionally mapped onto Consideration, a multidimensional assessment of what consumers have already done vis-à-vis two types of ZEVs: battery and fuel cell electric vehicles (BEVs and FCEVs). Results indicate that active consumer resistance did not abate for BEVs over the study period, and that while it did abate slightly for FCEVs the probability of active resistance became less dependent on assessments of FCEV performance, fuel availability, or comparisons to conventional gasoline-fueled...

Incorporating Infrastructure and Vehicle Technology Requirements, Changes in Demand, and Decarbonization Policies' Considerations into Freight Planning

Wed, 17 Sep 2025 00:00:00 +0000

This report develops an equitable and sustainable freight-oriented land use (LU) methodology to support future planning activities, enabling the integration of freight activity across urban, suburban, and rural areas and facilitating the transition of heavy- and medium-duty vehicles toward zero-emission. The methods include a literature review to identify freight sustainable strategies, policy analysis at different scales, characterization of local context, and demand/supply patterns. The latter examines the spatial distribution and land use characteristics of freight facilities and retail/service sectors in the Sacramento region to inform sustainable and equitable planning strategies. This analysis identifies co-location patterns, accessibility gaps, and sectoral interactions using a multi-dimensional approach integrating spatial clustering, distance analysis, population-employment dynamics, and environmental burdens. Data sources include Longitudinal Employer-Household Dynamics...

Data Collection of Odometer Images via WhatsApp to Measure Vehicle Miles Traveled

Wed, 17 Sep 2025 00:00:00 +0000

California sets ambitious climate goals that demand a sharp reduction in the per-capita vehicle miles traveled (VMT). Traditionally, researchers have relied on three types of VMT data collection methods – travel surveys, passively collected data, and simulated data – to estimate VMT or understand factors affecting VMT. However, each of these methods has disadvantages for obtaining a reliable VMT dataset. Although travel surveys are an inexpensive way to collect VMT data with rich traveler attributes, they often suffer from bias and errors in reporting or recalling. Passively collected VMT data, such as traffic count data, can provide precise VMT data, yet they often lack information about “who” and “why” of travel. Lastly, simulated VMT data is useful when making counterfactual testing, but they are after all not real data. In this study, to fulfill the gap between current data collection strategies, the authors introduce a WhatsApp-based VMT data collection framework....

Qualitative Evaluation of the Yolobus BeeLine Microtransit Service

Wed, 17 Sep 2025 00:00:00 +0000

In response to challenges with providing fixed route transit in rural areas, many transit agencies in the United States and around the world are increasingly looking towards microtransit, a form of flexible route transit service which can be reserved on-demand, to provide transit service in rural areas. However, the immaturity of microtransit relative to conventional fixed route transit means that the benefits and challenges of microtransit in rural areas are still not fully understood. This paper aims to identify these benefits and challenges through the evaluation of a case study microtransit system—the Yolobus BeeLine. The BeeLine is a microtransit service provided by Yolobus, the transit agency operating in Yolo County, California, and is unique in that it operates in both low-density rural and medium-density suburban areas. By conducting ride-along interviews with riders of the BeeLine service, the authors investigate the benefits of the microtransit service for its riders...

Electric Truck Fleet Management under Limited and Uncertain Charging Infrastructure Availability

Wed, 17 Sep 2025 00:00:00 +0000

The transition to zero-emission freight transportation is a critical component of California’s climate strategy, yet the adoption of battery electric trucks (BETs) in both long-haul and short-haul operations faces significant challenges. Limited charging infrastructure, long charging durations, grid reliability concerns, and regulatory constraints—such as Hours of Service (HOS) requirements—pose operational hurdles for fleet operators. This study develops a comprehensive optimization framework for electric truck fleet management, addressing the interplay between infrastructure limitations, operational uncertainties, and energy cost fluctuations. This research will also provide scalable insights for policymakers and industry leaders, supporting the broader transition to sustainable freight transportation. Investments in ultra-fast charging infrastructure, extended-range BETs, and microgrid-based energy management are key to accelerating the electrification of freight operations...

MOVES 4.0 Updates for the Fuel and Emissions Calculator (FEC)

Mon, 11 Aug 2025 00:00:00 +0000

This project employs the outputs from MOVES-Matrix 4.0 to generate a data set that can be employed by users of the 2018 Fuel and Emissions Calculator (Version 3.0) to update energy use and emission rates to reflect the latest outputs from the U.S. Environmental Protection Agency’s (USEPA’s) MOVES 4.0 energy use and emission rate model for the Atlanta, Georgia summer scenario. The data employed in this project were generated as part of the National Center for Sustainable Transportation project entitled MOVES-Matrix 4.0 for High-Performance On-road Energy Use and Emission Rate Modeling Applications (Lu, et al., 2025). As described in this report, the team queried more than 90 billion cells within full MOVES-Matrix 4.0 data set to generate MOVES 4.0 data that can be substituted for the older MOVES 2014 data in Fuel and Emissions Calculator (FEC) Version 3.0 for Georgia. The query output data are contained in an Excel spreadsheet, allowing users to update their personal copies...

MOVES-Matrix 4.0 for High-Performance On-road Energy Use and Emission Rate Modeling Applications

Wed, 23 Jul 2025 00:00:00 +0000

This study introduces MOVES-Matrix 4.0, an innovative high-performance implementation of MOVES 4.0.1 that generates exactly same energy and emission rate results as the Environmental Protection Agency’s latest version of MOVES 4.0.1, but allows users to deploy the MOVES model in complex and dynamic analyses. The team utilized the same conceptual design used in MOVES-Matrix 2014 and MOVES-Matrix 3.0, and updated the configurations on PACE supercomputing clusters to account for the programming changes with respect to MOVES databases (e.g., migration to MariaDB) and MOVES’ algorithm updates since MOVES2014b (e.g., extended VSP/STP parameters). The MOVES-Matrix 4.0 system develops sub-matrices of energy and emission rates by executing 181,818 MOVES runs to generate more than 5.8 trillion energy and emission rates in thepopulated matrix for a single modeling region (represented by a unique combination of fuel specification regime and inspection and maintenance program). Performance...

Exploring the Equity Effects of VMT Mitigation Measures

Wed, 2 Jul 2025 00:00:00 +0000

In 2018, pursuant to Senate Bill (SB) 743 (2013), the Governor’s Office of Planning and Research (OPR) and the California Natural Resources Agency promulgated regulations and technical guidance that eliminated automobile level of service (LOS) as a transportation impact metric for land development projects under the California Environmental Quality Act (CEQA), and replaced it with Vehicle Miles Traveled (VMT). The authors investigated the equity effects of VMT mitigation measures and developed a framework for evaluating those effects at the project level. The authors then applied the framework to two highway expansion case studies in California. They found that most VMT mitigation would be implemented at least partially within the project impact areas, as well as some disadvantaged communities, but would generally benefit communities outside of the project area, too. Most of the proposed mitigation measures would not displace existing residences or businesses or pose a significant...

Advancing Active Transportation Project Evaluation

Wed, 11 Jun 2025 00:00:00 +0000

The purpose of this study is to examine the effectiveness of active transportation projects in increasing active transportation in California. It also serves to validate the current methods of the California Active Transportation Benefit-Cost Tool. Using count and infrastructure data from the cities of Santa Barbara and Santa Cruz, California, with updated models from the California Active Transportation Benefit-Cost Tool, the authors estimated project level changes in active transportation using two methods. The first method uses a direct demand modeled before and after bicycling and pedestrian volumes. The second method is an expected increase in bicycling and pedestrian volumes based on the project parameters and their effect sizes from the academic literature. Results show that, in general, both estimates are closely aligned. However, the results also indicate that for some projects, particularly those projects with greater change in walking and bicycling, the California...

Enhancing Extreme Weather Resilience for Rail Systems: Multi-Capability Performance Monitoring Approach & Sustainability Integration

Tue, 10 Jun 2025 00:00:00 +0000

Resilience for rail systems may be defined by the set of system capabilities that enable the continued or improved functionality of rail systems exposed to multiple types of hazards, including extreme weather events. Assessing the resilience of rail systems and making appropriate investments may reduce the impacts of threats to system users and infrastructure. However, no studies found by the authors to date have proposed a comprehensive set of metrics that address all the commonly cited resilience capabilities: robustness, flexibility, preparedness, survivability, recoverability, adaptive capacity, and transformative capacity. Based on a review of studies across freight, intercity passenger, and urban transit rail systems, metrics for resilience are identified, categorized, and analyzed along the disruption and recoverytimeline (from before disruption occurrence to long after system recovery). The intent of reviewing such a diverse set of rail system studies is to find appropriate...

Wildlife Connectivity and Which Median Barrier Designs Provide the Most Effective Permeability for Wildlife Crossings

Tue, 27 May 2025 00:00:00 +0000

Median barriers are usually constructed to reduce head-on-crashes between vehicles on undivided highways. Because of their position in the center of the traveled right-of-way, median barriers could affect wildlife movement across the right-of-way, decreasing wildlife connectivity. The authors coordinated and met with staff from several Caltrans Districts to gain understanding of their issues related to median barriers and wildlife permeability. The authors used previously and newly collected wildlife-vehicle collision (WVC) observations to test whether or not median types have different effects on unsuccessful wildlife crossings of the road surface. The authors used Generalized Linear Models (GLM) to compare WVC rates among median treatment types in three Caltrans Districts (2, 4, 9) for four wildlife species. The primary findings were that there are effects of median types on rates of WVC and that these effects varied by species and to some degree by geographic region (represented...

Lab2Slab2Practice: A Framework for a Faster Implementation of Innovative Concrete Materials and Technology

Mon, 5 May 2025 00:00:00 +0000

Transportation infrastructure construction and maintenance consume energy and finite resources, and have substantial environmental impacts, primarily from the manufacturing of cement, concrete, asphalt, and steel. New feedstock materials and technologies for producing these materials can result in lower life cycle costs, use of local materials, creation of local employment, and reduced environmental impacts. These goals point to the urgent need for adopting innovative alternatives. However, implementation requires confidence on the part of materials producers, contractors, and infrastructure owners that the new materials and technologies can achieve these goals. Implementation demands rigorous testing, risk management, and stakeholder confidence in the engineering performance, environmental benefits, and economic viability of new materials and technologies. This report introduces a structured evaluation framework, “Lab2Slab2Practice,” aimed at accelerating the adoption of these...

Exploring the Induced Travel Effects from Minor Arterials, Auxiliary Lanes, and Interchanges

Mon, 5 May 2025 00:00:00 +0000

A robust body of empirical research demonstrates that as roadway supply increases, vehicle miles traveled (VMT) generally does, too. The evidence is particularly strong with respect to major roadways, like interstate highways (class 1), other freeways and expressways (class 2), and principal arterials (class 3). However, previous literature reviews have found limited empirical evidence as to the relative magnitude of the induced travel effect of expanding minor arterials, collector streets, and local roads. Previous reviews have similarly not reported empirical research on the induced travel effects of other types of roadway facilities, such as auxiliary lanes, ramps, or other types of interchanges. In this project, the authorsconducted a systematic literature review on the induced travel effects of minor arterials, auxiliary lanes, and interchanges (including simple on/off ramps). The authors found that the empirical literature remains limited with respect to auxiliary lanes...

Real-Time Large-Scale Ridesharing with Flexible Meeting Points

Wed, 30 Apr 2025 00:00:00 +0000

In this report, the authors propose an online and large-scale rideshare system that can dynamically match passenger requests with drivers and provide efficient routes to the drivers. The authors developed a greedy insertion-based routing procedure to route thousands of requests in an hour. They incorporated flexible meeting point selection into the framework, which can reduce travel distances for both drivers and passengers. The authors implemented an online incentive and cost-sharing system that can incentivize drivers and passengers for their ride time limit violations and share the cost of a rideshare trip among the passengers fairly. The authors incorporated a request prediction and detour mechanism into the ridesharing framework. To get the most updated travel time and study the effects of ridesharing in a road network, theauthors also incorporate a simulation approach into the framework. Numerical experiments performed on the New York Taxicab dataset and a rural dataset...

CO2 and Cost Impact Analysis of a Microgrid with Electric Vehicle Charging Infrastructure: A Case Study in Southern California

Tue, 1 Apr 2025 00:00:00 +0000

As a part of an innovative Intelligent Transportation System (ITS), this paper investigates the effectiveness of transportation-based microgrid configurations in reducing carbon dioxide (CO₂) emissions and electricity costs. A case study at the University of California, Riverside (UCR) utilizes high-resolution California Independent System Operator (CAISO) CO₂ emission data to assess the environmental impact of each microgrid configuration. It also compares electricity costs to determine potential consumer savings. The results demonstrate that a load-following transportation microgrid strategy can significantly reduce CO₂ emissions (67%–84%) and achieve annual cost savings of approximately $24,000, even when accounting for the additional demand from daily electric vehicle (EV) charging at the building. However, battery sizing is crucial for cost-effectiveness, as load-following exhibits diminishing returns. Doubling battery capacity may yield...

Advanced Battery Technologies: Bus, Heavy-Duty Vocational Truck, and Construction Machinery Applications

Wed, 26 Mar 2025 00:00:00 +0000

This report examines the electrification of buses, vocational trucks, and construction machinery, as well as the impact of advancements in battery technology on this transition. The electrification of these vehicles and machinery, alongside rapid progress in battery development, is accelerating. This study provides a comprehensive review of current research on lithium-ion and sodium-ion batteries, evaluating their development status and the challenges to commercialization. A keyobjective of this study is to assess the progress of advanced battery development and its influence on the further commercialization of buses, vocational trucks, and construction machinery. Modeling suggests that within the next 7 to 12 years, batteries with energy densities of 500 Wh/kg and 1000 Wh/L will enable electrified construction vehicles andmachinery to match or surpass the performance of current diesel-powered equipment. Electric buses are already commercially available and expanding globally,...

Sensitivity Testing of Induced Highway Travel in the Sacramento Regional Travel Demand Model

Wed, 19 Mar 2025 00:00:00 +0000

Since the 1970s, stakeholders have expressed concerns about the ability of transportation travel demand used by metropolitan planning organizations to represent induced travel from expanded highway capacity. Failure to adequately represent induced travel will underestimate vehicle miles traveled and congestion when comparing scenarios with and without highway capacity expansion. To examine the magnitude of potential biases, the authors use the state-of-the-practice transportation demand model, the Sacramento Council of Governments (SACOG) SACSIM19 model, to examine (1) the model's representation of induced travel, (2) the influence of variation in key inputs on vehicle travel and roadway congestions, and (3) the effect of changes in induced travel-related input variables on the comparisons of scenarios with and without highway expansions.

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Caltrans 2024 Sustainable Freight Academy

Wed, 12 Mar 2025 00:00:00 +0000

The Caltrans 2024 Sustainable Freight Academy was held on November 18-21, 2024. The academy consisted of presentations from goods movement professionals and subject matter experts, including those from both public and private organizations. The final group presentation allowed participants to develop their skills in grant writing by applying lessons learned from the course. Participants were divided into eight groups and took on various roles such as Grant Writer, Project Manager, and Industry Partner in order to develop and present a mock Trade Corridor Enhancement Program (TCEP) proposal topic.
View the NCST Project Webpage

Mitigating Extreme Heat Exposure Using Advanced and Novel Materials and Improved Pedestrian Infrastructure Design: A Systematic Literature Review and Survey of Agencies

Tue, 18 Feb 2025 00:00:00 +0000

Extreme heat is the leading cause of weather-related mortality in the United States, and extreme heat events are projected to continue to increase in geographic extent, frequency, and severity in the United States as climate change progresses. Transportation infrastructure is a significant driver of the urban heat island (UHI) effect and exacerbating extreme heat events. Efforts to mitigate UHI impacts often focus on reflecting incoming solar radiation (i.e., increasing surface albedo) and providing shade (e.g., planting street trees). However, advanced and novel materials (ANM) for pavements that reduce heat storage, and green stormwater infrastructure (GSI) that promotes evaporative cooling, can provide additional heat mitigation pathways. Sidewalks facilitate non-motorized transportation, and are relatively low-risk, low-cost, and have simple structural requirements compared to other transportation infrastructure. Hence, sidewalks and adjacent planting strips can offer a...

Quantifying Reductions in Vehicle Miles Traveled from New Pedestrian Facilities: Technical Documentation

Tue, 18 Feb 2025 00:00:00 +0000

This report summarizes research outcomes in an effort to update the California Air Resources Board (CARB)’s current methodology for estimating greenhouse gas (GHG) emission reductions from adding new pedestrian facilities, including sidewalks and shared-use Class I bicycle paths. At least three programs offer Greenhouse Gas Reduction Fund (GGRF) funding for projects with new pedestrian facilities. To measure GHG emissions reductions from new pedestrian facilities, CARB currently relies on a method (the “congestion mitigation and air quality improvement (CMAQ) method”) it published with Caltrans in 2005 for calculating GHG emissions reductions from new bicycle facilities. The data on which that method is based are even older, mostly from the 1990s. This report reviews the more recent literature to determine whether and how the CMAQ method could be modified to better reflect emerging data and methods. This review summary focuses on the first—and most difficult—step in the GHG...

Revisiting Average Trip Length Defaults and Adjustment Factors for Quantifying VMT Reductions from Car Share, Bike Share, and Scooter Share Services

Tue, 18 Feb 2025 00:00:00 +0000

Under California’s Cap-and-Trade program, the State’s portion of the proceeds from Cap-and-Trade auctions is deposited in the Greenhouse Gas Reduction Fund (GGRF). The Legislature and Governor enact budget appropriations from the GGRF for State agencies to invest in projects that help achieve the State’s climate goals. These investments are collectively called California Climate Investments. Senate Bill (SB) 862 requires the California Air Resources Board (CARB) to develop guidance on reporting and quantification methods for all State agencies that receive appropriations from the GGRF. CARB may review and update quantification methodologies, as needed. CARB developed quantification methodologies to provide project-level GHG estimates for administering agencies to use when selecting projects for funding. CARB’s quantification methods use a similar formula to measure GHG emissions reductions from both new bike share programs and new car share programs. That formula includes as...

Quantifying Reductions in Vehicle Miles Traveled from New Bike Paths, Lanes, and Cycle Tracks: Technical Documentation

Tue, 18 Feb 2025 00:00:00 +0000

This report summarizes research outcomes in an effort to update the California Air Resources Board’s (CARB) current methodology for estimating greenhouse gas (GHG) emission reductions from adding new bicycle paths, lanes, and cycle tracks. At least three programs offer Greenhouse Gas Reduction Fund (GGRF) funding for projects with new bicycle facilities. They include the California Strategic Growth Council’s Affordable Housing and Sustainable Communities (AHSC) Program, the Natural Resources Agency’s Urban Greening Grant Program (Urban Greening) and the California Department of Transportation’s (Caltrans) Active Transportation Program (ATP). To measure GHG emission reductions from new bike paths and lanes, CARB currently relies on a method it published with Caltrans in 2005 for evaluating motor vehicle fee registration projects and congestion mitigation and air quality (CMAQ) improvement projects. The data on which the CMAQ method is based are even older, mostly from the 1990s...

Updated Default Values for Transit Dependency and Average Length of Unlinked Transit Passenger Trips, for Calculations Using TAC Methods for California Climate Investments Programs: Technical Report

Tue, 18 Feb 2025 00:00:00 +0000

This report addresses aspects of the California Air Resources Board (CARB)’s current quantification methods for estimating GHG emission reductions from projects that expand transit facilities or service. A number of California Climate Investments programs fund transit projects, including the Low Carbon Transit Operations Program, the Transit and Intercity Rail Capital Program, and the Affordable Housing and Sustainable Communities Program. CARB has developed technical documents for each program, called “Quantification Methodologies,” and associated spreadsheet calculation tools, called “Benefit Calculator Tools,” for program applicants to use in estimating project-level GHG emission reductions and co-benefit estimates for projects proposed for funding. To measure GHG emission reductions from transportation projects, including transit projects, CARB relies on ”CMAQ” computation methods, published by CARB in 2005 with the California Department of Transportation (Caltrans) for...

Updated Default Values for Transit Dependency and Average Length of Unlinked Transit Passenger Trips, for Calculations Using TAC Methods for California Climate Investments Programs: Summary Report

Tue, 18 Feb 2025 00:00:00 +0000

The California Air Resources Board (CARB) has developed quantification methods to provide project-level greenhouse gas (GHG) and co-benefit estimates for administering agencies to use when selecting projects for funding from California Climate Investments programs. To measure GHG emission reductions from transportation projects, CARB relies on a method it published with the California Department of Transportation (Caltrans) in 2005 for evaluating motor vehicle fee registration projects and congestion mitigation and air quality improvement (CMAQ) projects, specifically transit and connectivity (TAC) features. This report addresses whether and how CARB might update two adjustment factors in the TAC methods that apply to transit facility and/or service expansion projects. The first factor is used to account for transit dependency in estimating ridership gains from a new transit project, by indicating the share of new riders who could be expected to have driven in the absence of...

Incentive Regulation of Transportation Network Companies

Tue, 18 Feb 2025 00:00:00 +0000

Transportation network companies (TNCs) like Uber and Lyft have revolutionized metropolitan transportation, surpassing traditional taxis in usage and rivaling bus ridership in the U.S. Despite their rapid growth, there has been limited analysis of appropriate policy responses. This project explored policy issues stemming from TNCs’ “economies of density,” where increased vehicle and customer density reduces wait and idle times, giving large TNCs a competitive advantage over smaller ones and taxis. This raises concerns about industry monopolization and regulatory disparities. The project’s objective was to explore whether and how TNCs should be regulated, as evidenced by policy developments like New York City's cap on TNC vehicles and the establishment of a minimum wage for TNC drivers. These measures address traffic congestion and the economic challenges faced by taxi drivers, with other cities considering similar actions. Additionally, the project incorporated insights from...

Quantifying Emissions of Natural Gas Storage Tanks in the Greater Los Angeles Metropolitan Area

Tue, 18 Feb 2025 00:00:00 +0000

Natural gas provides an alternative to petroleum-based fuels as an energy source that is being more widely adopted across multiple sectors in California. The viability of natural gas depends on its total life cycle emissions, specifically of those of methane. This paper addresses the possibility of and reason for fugitive emissions of methane from the transportation sector by surveying and quantifying methane plumes from compressed natural gas (CNG) and liquified natural gas (LNG) storage tanks at vehicle fueling facilities in the greater Los Angeles metropolitan area. This project used methane plume images provided by airborne imaging spectroscopy, collected by NASA’s AVIRIS-NG mission, to identify large methane point sources originating from CNG and LNG infrastructure. The periodic methane plume observations were converted into emission rates to provide an estimate for potential methane emissions from NG storage facilities across California. For the population of facilities...

Quantifying Reductions in Vehicle Miles Traveled from New Pedestrian Facilities: Summary Report

Tue, 18 Feb 2025 00:00:00 +0000

Under California’s Cap-and-Trade program, the State’s portion of the proceeds from Cap-and-Trade auctions is deposited in the Greenhouse Gas Reduction Fund (GGRF). The Legislature and Governor enact budget appropriations from the GGRF for State agencies to invest in projects that help achieve the State’s climate goals. These investments are collectively called California Climate Investments. Senate Bill (SB) 862 requires the California Air Resources Board (CARB) to develop guidance on reporting and quantification methods for all State agencies that receive appropriations from the GGRF. CARB may review and update quantification methodologies, as needed. CARB developed quantification methodologies to provide project-level greenhouse gas (GHG) emission reduction and co-benefit estimates for administering agencies to use when selecting projects for funding. To measure GHG emission reductions from new pedestrian facilities, CARB relies on a method it published with the California...

Quantifying Reductions in Vehicle Miles Traveled from New Bike Paths, Lanes, and Cycle Tracks: Summary Report

Tue, 18 Feb 2025 00:00:00 +0000

Under California’s Cap-and-Trade program, the State’s portion of the proceeds from Cap-and-Trade auctions is deposited in the Greenhouse Gas Reduction Fund (GGRF). The Legislature and Governor enact budget appropriations from the GGRF for State agencies to invest in projects that help achieve the State’s climate goals. These investments are collectively called California Climate Investments. Senate Bill (SB) 862 requires the California Air Resources Board (CARB) to develop guidance on reporting and quantification methods for all State agencies that receive appropriations from the GGRF. To date, multiple California Climate Investments programs have offered funding for new bicycle paths or lanes. CARB developed quantification methodologies to provide project-level greenhouse gas (GHG) emission reduction and co-benefit estimates for administering agencies to use when selecting projects for funding. To measure GHG emission reductions from new bike paths and lanes, CARB relies on...

Improving Public Safety Through Spatial Synthesis, Mapping, Modeling, and Performance Analysis of Emergency Evacuation Routes in California Localities

Mon, 10 Feb 2025 00:00:00 +0000

This project examines multi-hazard risks and the performance of emergency evacuation routes in California using spatial synthesis, mapping, modeling, and performance analysis techniques. It enhances evacuation planning by analyzing road networks under natural hazard scenarios. Key tasks included: 1. Collecting and organizing evacuation route data for 190 cities, revealing that only 23 had comprehensive GIS maps, highlighting gaps in current planning. 2. Assessing road network performance under various hazards for 450 cities, identifying high-risk areas, and classifying cities based on risk levels and concentration. 3. Analyzing evacuation routes during the 2018 Camp and Thomas fires, using mathematical modeling and Omniscape to assess bottlenecks and evacuation efficiency. 4. Evaluating evacuation route performance for different population segments and proposing improvements, including using public transit for future wildfire evacuations. The findings provide actionable insights...

Ecosystem of Shared Mobility Services in the San Joaquin Valley

Wed, 5 Feb 2025 00:00:00 +0000

This report presents the results of the Ecosystem of Shared Mobility Services in the San Joaquin Valley (Ecosystem) pilot project. The project is part of California Climate Investments (CCI), a statewide initiative that puts billions of Cap-and-Trade dollars to work reducing greenhouse gas emissions, strengthening the economy, and improving public health and the environment — particularly in disadvantaged communities. As the grantee for this pilot project, the San Joaquin Valley Air Pollution Control District implemented the pilot program by partnering and/or subcontracting with several local entities including, but are limited to: Sigala Inc.; UC Davis, Institute of Transportation Studies; Shared-Use Mobility Center (SUMC); Self-Help Enterprises, and MOVE. Funding for the Ecosystem pilot project provided by a grant from the California Air Resources Board (CARB) through the Car Sharing and Mobility Option Pilot Project solicitation. Research for the project was also supported...

Survey and Analysis of Transportation Affordable Programs in California

Tue, 4 Feb 2025 00:00:00 +0000

While the United States has long supported basic needs of residents through social welfare programs, policies supporting affordable transportation for lower income individuals have been much more limited. Federal support for transportation includes subsidies to transit agencies and requirements to offer discounted fares to certain groups such as seniors and riders with disabilities, but income-qualified discounts are not required. This study explores opportunities for improving access to transportation affordable programs by gathering insights from existing income qualified transportation benefits. Researchers compare examples of these programs to design features of existing non-transportation benefits to characterize opportunities for increased coordination and standardization. Finally, as the U.S. has seen an increase in recent years of Universal Basic Mobility (UBM) pilots that provide flexible transportation funds, the study incorporates insights from UBM evaluations to...

Energy and Emissions Impacts of Atlanta’s Reversible Express Toll Lanes and High-Occupancy Toll Lanes

Thu, 30 Jan 2025 00:00:00 +0000

This report summarizes the impact on corridor-level energy use and emissions associated with the 2018 opening of the I-75 Northwest Corridor (NWC) and I-85 Express Lanes in Atlanta, GA. The research team tracked changes in vehicle throughput on the managed lane corridors (extracted from GDOT’s Georgia NaviGAtor machine vision system after comprehensive QA/QC) and performed a difference-in-difference analysis to exclude regional changes, pairing test sites vs. control sites not influenced by the openings. The results show a large increase in overall peak-period vehicle throughput on the NWC, especially on I-575, due to the congestion decrease (20 mph speed increases at some locations). The increase in corridor-level energy use and emissions was smaller than vehicle throughput, but still significant. Predicted downwind maximum CO concentrations only increased from 1.81 ppm to 1.93 ppm (which remains extremely low). The increase in morning peak activity on the corridor likely...

Barriers to Reducing the Carbon Footprint of Transportation Part 3: The Impact of the Covid-19 Pandemic on Travel Patterns

Tue, 28 Jan 2025 00:00:00 +0000

Vehicle travel, measured as vehicle-miles traveled (VMT), dropped precipitously in California following “stay-in-place” orders issued by the state and counties as a response to the Covid-19 pandemic. Although VMT rebounded relatively quickly, the state has an opportunity to leverage other changes in household travel behavior so as to achieve its VMT reduction goals while enhancing transportation equity. This report reviews the available evidence on changes in household travel behavior resulting from the Covid-19 pandemic and provides an overview of potential state, regional, and local-level policies that could help to preserve changes that help to reduce VMT and reverse those that tend to increase VMT. The review focuses on alternatives to driving, specifically telecommuting, public transit, ride-hailing, e-shopping, and active travel and micro-mobility.
View the NCST Project...

Barriers to Reducing the Carbon Footprint of Transportation Part 1: Support to the Clean Miles Standard Policy Making

Tue, 28 Jan 2025 00:00:00 +0000
Transportation Network Companies (TNCs), also referred to as ridehailing companies, have experienced rapid growth in the past decade. This report focuses on the quickly evolving transportation patterns resulting from the adoption of ridehailing as part of the efforts accompanying the implementation of the Clean Miles Standard (CMS) regulation. Based on the analysis of survey data collected in four California metropolitan regions before the COVID-19 pandemic, this report summarizes the findings from three studies, focusing on (1) the use of ridehailing among traveler groups with different multimodal travel patterns, (2) the substitution of ridehailing for other modes, and travel induced by ridehailing, and (3) the use of pooled ridehailing services, in which multiple passengers share the same vehicle for all or a portion of their trips. The results from these analyses reveal that transit users are more likely to be ridehailing users. Individuals without a household vehicle and...

EVALUATE: Electric Vehicle Assessment and Leveraging of Unified models toward AbatemenT of Emissions, Phase I

Mon, 27 Jan 2025 00:00:00 +0000

This research explores electric vehicle (EV) and grid interactions with a focus on CO2 emissions for future scenarios where EVs comprise growing market shares (e.g., 10% of the overall fleet mix). A major contribution of this effort has been to develop a methodology that integrates sub-system models and datasets that have previously stood alone, namely models and data that characterize: vehicle energy consumption, travel demands, vehicle charging, and temporal emission profiles associated with electric power generation dispatch. This convergence research helps quantify the relative emissions of light duty vehicle use and charging during various times of day to enable comparison of EV modes against one another and against conventional vehicle baselines. An initial use case involving light duty commuter and recharging scenarios has been explored as a means of validating and tuning the methodology. Under certain simulated scenarios, observed marginal emissions can be as much as...

US-Mexico Second-Hand Electric Vehicle Trade: Battery Circularity and End-of-Life Policy Implications

Mon, 27 Jan 2025 00:00:00 +0000

International second-hand vehicle (SHV) exports are a multi-billion-dollar market for the US and an integral process in removing older vehicles from the road and enabling a robust new vehicle market. Mexico is the largest importer of SHVs from the US. As the US rapidly increases electric vehicle (EV) sales to meet decarbonization targets for the transportation sector, EVs will be an increasing large fraction of SHVs. While the benefits of EV adoption are numerous, introducing a radically new technology such as EVs without responsive measures in second-hand market regions may lead to an unintended transfer of economic and environmental burdens, especially if waste EV batteries cannot be managed properly. This research undertook a battery material flow analysis, life cycle assessment of SHVs traded from the US to Mexico, and a qualitive analysis of environmental and transport justice implications of SHV trade. The research finds that SHVs disproportionately contribute to waste...

Assessing the Growth of Multi-EV Households in California

Mon, 27 Jan 2025 00:00:00 +0000

To meet zero-emission vehicle targets, consumers will have to adopt electric vehicles and convert their entire fleets. In the United States and California, most households own two or more vehicles; most of these households will need to switch their traditional vehicles for plug-in electric vehicles (PEVs). However, most of the research on PEV adoption has focused on people acquiring their first PEV. This work is the first to examine households’ decision to maintain at least two PEVs in their household fleets. Utilizing a multi-year survey of PEV adopters between 2012 and 2020, 3,039 respondents who acquired a vehicle after obtaining an initial PEV are identified. Respondents are divided in two groups: those who reverted to an internal combustion engine vehicle (Single PEV) and those who added an additional PEV (Multi PEV). Modelling the groups using binary logistic regression, several factors that differentiate Single from Multi PEV households are identified. Compared to Single...

Cost Sensitivity and Charging Choices of Plug-in Electric Vehicle Drivers – A Stated Preference Study

Mon, 27 Jan 2025 00:00:00 +0000

California's Zero Emission Vehicle (ZEV) mandate targets all new Light Duty Vehicle (LDV) sales to be ZEVs by 2035. However, the current charging infrastructure is not well-developed in California, primarily serving households with home charging setups and leaving a noticeable gap in public charging facilities. This gap is seen as a significant barrier to Battery Electric Vehicle (BEV) adoption within California. This report explores driver charging behavior and their preference for public DC fast charging (DCFC), drawing on Stated Preference (SP) choice experiment data from a survey of 1,102 Plug-in Electric Vehicle (PEV) owners across California.
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EVALUATE: Electric Vehicle Assessment and Leveraging of Unified models toward AbatemenT of Emissions, Phase II

Mon, 27 Jan 2025 00:00:00 +0000

The EVALUATE (Electric Vehicle Assessment and Leveraging of Unified models toward AbatemenT of Emissions) project (Phases I and II) develops a rigorous methodology involving a high-fidelity system of systems model (i.e., vehicle powertrain, EV charging profiles and grid dispatch datasets) for the purpose of forecasting the emissions outputs of a class of vehicles and use cases. Phase I findings explored urban trips by households that operate light duty vehicles (LDVs) for daily personal use. Phase II, presented here, focuses on a series of targeted case studies that extend prior work from LDVs operated by individuals to service-oriented vehicles operated by small and medium businesses. Vehicles used in the present study are representative of public service fleets including the following: pickup trucks, vans, Medium Duty (MD) delivery vehicles, and refuse trucks. In one of the study’s simulations for a MD use case where a specific marginal grid generating resource is identified...

Evaluating Carpool Potential for Home-to-Work SOV Commuters Using a Scalable and Practical Simulation Framework

Mon, 27 Jan 2025 00:00:00 +0000

Given that morning peak period vehicle occupancy rates are generally 1.1 to 1.2 persons per vehicle in urban areas, transportation planners have long argued that effective carpooling strategies could significantly reduce traffic congestion and the carbon footprint of commuters. Community-based carpooling, which is designed to match drivers and passengers that reside within subregions and that are traveling to similar destination zones, can be exploited once technology, communication, demographic, and economic barriers are overcome. While community-based carpool has the potential to provide sustainability benefits, integration into transportation plans and models is not prevalent, due to the lack of appropriate analytical tools. CarpoolSim is a new scalable analytical framework designed evaluate the potential performance and impact of intelligent carpooling system (ICS) for regional networks. Designed to be directly integrated into the travel demand modeling process, CarpoolSim...

Evaluating Heterogeneity in Household Travel Response to Carbon Pricing: A Study Focusing on Small and Rural Communities

Mon, 27 Jan 2025 00:00:00 +0000

Smaller and rural communities are often automobile dependent, a fact that has raised considerable concerns about the equity and effectiveness of market-based climate strategies including carbon taxes and carbon cap and trade schemes in rural states like Vermont. A lack of research and data describing how people in smaller and rural communities respond to changes in transportation costs is a critical gap to informing the design of market-based greenhouse gas mitigation policies and evaluating their potential outcomes. This report describes several related studies that focus on understanding the opportunities and constraints that people face in changing how they travel in small and rural communities in Vermont and also evaluates the equity implications of gas tax alternatives. The research is informed by data collected by the researcher team from interviews, surveys and unique administrative datasets. Findings show that urban, suburban, and rural households all made significant...

Transit Use During and After the COVID-19 Pandemic: The “New Normal” for Public Transit Ridership

Sat, 25 Jan 2025 00:00:00 +0000

The Covid-19 pandemic significantly impacted transit ridership across Canada. As the pandemic begins to subside, understanding the factors that influence peoples’ decisions to use transit (or not) is crucial for the recovery and long-term sustainability of public transit. Using data from the third wave of the Public Transit and Covid-19 survey in Canada, this study evaluates who returned to pre-pandemic transit use, the factors influencing the decision to ride transit, and peoples’ intentions for future transit use. The authors find that most transit riders perceive that the pandemic is over but its effects are here to stay, though they are split about whether the pandemic still affects their transit use. While some transit riders have gradually returned to pre-pandemic transit levels, a relatively small share of those who have not yet fully returned intend to and a significant proportion do not intend to fully return. About half of transit riders will return to transit at...

Integrated Modeling Program and Total Cost of Ownership Calculator for Medium-Duty and Heavy-Duty Battery Electric Trucks in Regional Freight Use-Case Deployments

Sat, 25 Jan 2025 00:00:00 +0000

This report outlines the technical development and application of the Total Cost of Ownership Spreadsheet Tool (TCOST), a Microsoft Excel-based calculator that simplifies and integrates the main functions, data, and outputs of pre-existing models (MOVES-Matrix and the GREET Model) and other external sources of economic data. The tool accommodates twenty-one user-input variables to produce comparative total cost of ownership figures for diesel and battery-electric trucks within any use case, broken down by cost type (capital, operation, and maintenance), both as a gross number and on a per-mile basis. The tool also provides a series of visualizations comparing cost breakdowns, breakeven points, and expected tailpipe and fuel-cycle emissions for both technologies. A hypothetical regional container drayage use-case example was developed using quantitative and qualitative data, to which TCOST was applied to demonstrate the application of the tool and its value to fleet managers...

Evaluation of Rural Travel Constraints and Travel Burdens in the U.S. and in Rural Zero-Car Households

Thu, 16 Jan 2025 00:00:00 +0000

The challenge of meeting transportation needs is heightened in rural contexts, where destinations are more dispersed and there are fewer transportation options. A growing body of literature has established that accessibility, or the ability to reach valued destinations, is critical to satisfying a person’s fundamental needs. Conversely, difficulty accessing destinations can result in travel burdens such as high transportation costs or unmet needs, adversely affecting well-being. This study evaluates differences in travel burdens and the factors that drive them in rural and urban contexts in the United States. Using the 2017 National Household Transportation Survey, the authors first evaluate differences in travel burdens across rural versus urban communities, including i) the magnitude of travel burdens, ii) who experiences travel burdens, and iii) the individual and environmental factors that are associated with travel burdens. This study finds that people living in rural...

Can Smart Growth Reduce Vehicle Travel in Rural Communities?

Thu, 16 Jan 2025 00:00:00 +0000

Reducing greenhouse gas emissions from transportation poses a significant challenge in the exurban fringe and rural communities. Populations living in these areas rely more heavily on personal vehicle travel than nonrural populations and are more likely to experience mobility challenges. One approach to curtailing these emissions is building more compact development or smart growth. However, nearly all research to date on travel and the built environment has focused on urban and suburban areas, leaving decision-makers in exurban and rural communities with little guidance for how to effectively reduce GHGs in their communities. To address this gap, travel behavior data from the Federal Highway Administration’s National Household Travel Survey is combined with detailed built environment data from the Environmental Protection Agency’s Smart Location Database to evaluate the relationships between personal and built environment factors and sustainable travel behaviors including...

A Modeling Framework for Near-Road Population Exposure to Traffic-Related PM2.5 and Environmental Equity Analysis: A Case Study in Atlanta, Georgia

Tue, 14 Jan 2025 00:00:00 +0000

In this study, a modeling framework for population exposure to traffic-related PM2.5 with high spatiotemporal resolution is proposed and applied to the I-575/I-75 Northwest Corridor (NWC) in Atlanta, GA, for environmental equity analysis. The analyses retrieved trip data from the Atlanta Regional Commission’s (ARC) Activity-Based Model 2020 (ABM2020), after implementing path retention algorithms (Zhao, et al., 2019) to generate individual travel paths for more than 20 million predicted vehicle trips. Emission rates for each link were retrieved from MOVES-Matrix given the ABM link speed and facility type, the ARC’s county-level fleet composition data, and regional fuel properties and I&M program parameters. High-resolution downwind concentration profiles were predicted using EPA’s AERMOD microscale dispersion model with AERMET meteorology profiles for a huge array of receptors. Trip-end locations were derived from the ABM trip data, and the on-road trajectories for each...

Framework to Quantify the Life Cycle Greenhouse Gas Emissions from the Build-Out and Maintenance of Global Roadway Networks

Thu, 9 Jan 2025 00:00:00 +0000

The goal of this study was to develop a framework and first order estimate of the greenhouse gas (GHG) emissions from the build-out and maintenance and rehabilitation of the world’s roadway infrastructure networks from 2020 to 2050. The GHG emissions from road pavement emissions, bridges, and maintenance and rehabilitation were calculated by decade based on the existing road networks and the modelling of their expansion. For comparison, the GHG emissions from vehicle manufacture and operation were estimated. Regional comparisons and sensitivity analyses were then performed. Based on one mid-range scenario, GHG emissions from new road construction account for roughly 0.1 to 4% of regional road transportation GHG emissions depending on the region; existing road maintenance accounts for 0.32 to 3%; vehicle manufacturing for 4 to 13% of regional GHG emissions; vehicle operation accounts for 82% to 93% of regional GHG emissions; and road roughness is responsible for approximately...

Travel Demand Modeling and the Assessment of Environmental Impacts: A Literature Review

Thu, 9 Jan 2025 00:00:00 +0000

The purpose of this literature review is to assess what is currently known about the ability of travel demand forecasting models (TDMs) to provide accurate forecasts for different types of transportation plans and projects with respect to different outcome measures of interest. The role of TDMs in assessing the implications of highway expansions for vehicle miles of travel (VMT) and greenhouse gas (GHG) emissions is of particular interest given the current regulatory context. Relevant studies for this review were found using a variety of search terms in the Transport Research International Documentation (TRID) database and Google Scholar. The report reviewed the available studies with respect to the themes of limitations of the models, validity testing and sensitivity testing, and VMT forecasting.
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Assessment of California MPO Travel Demand Forecasting Models

Thu, 9 Jan 2025 00:00:00 +0000

The goal of this project was to assess the capabilities of the travel demand forecasting models (TDMs) used by California’s metropolitan planning organizations (MPOs) with respect to forecasting the increase in vehicle miles of travel induced by highway capacity expansion. An expert panel assisted with the development of review questions to be used in assessing the models. These questions were used to assess each of the models currently used by the eighteen MPOs in California based on information found in readily available documents. The assessment found that seven MPOs are using activity-basedmodels, nine are using four-step, trip-based models, and two are using hybrid models. In general, the activity-based models do a better job of capturing possible induced travel effects. Only one model includes explicit feedback between the transportation system and land use patterns. The readily-available documentation of travel demand forecasting models in California is insufficient...

MOVES-Matrix 3.0: On-Road Energy and Emission Modeling with High-Performance Supercomputing

Wed, 8 Jan 2025 00:00:00 +0000

The Georgia Tech research team developed MOVES-Matrix 3.0 based on the EPA's MOVES3 (version 3.1.0) energy use and emission rate model by running MOVES3 thousands of times on the PACE supercomputing cluster across all combinations of input variables and storing the output as lookup tables. MOVES-Matrix 3.0 allows on-road energy consumption and emissions modeling to be conducted more than 800 times faster than running MOVES, while it generates the exact same results, as verifiedin this report. MOVES-Matrix 3.0 was designed similarly to its predecessor, MOVES-Matrix 2014, but required extensive code modifications to accommodate changes in the MOVES3 environment (including a shift from MySQL to MariaDB and incorporation of new vehicle source sub-types and operating parameters). The review of the fuel and I/M scenarios indicated that MOVES3 now defines 122 modeling regions, as compared with 109 regions in MOVES 2014b (different matrices need to be developed each modeling region)....

Can We Align VMT and LOS Analysis and Mitigation? Assessing Implementation of Senate Bill 743

Wed, 8 Jan 2025 00:00:00 +0000

This report investigates how local governments (cities and counties) are implementing California’s Senate Bill 743, adopted in 2013 to eliminate traffic delay, measured using level-of-service (LOS) standards, as a basis for analyzing and mitigating transportation-related impacts of development projects and plans as called for under the California Environmental Quality Act (CEQA). Based on a survey of local planning directors in California, administered in Spring, 2024, the report finds that more thanfour-fifths of localities are continuing to apply LOS standards on an “off-CEQA” basis in the permitting process for individual development projects, as well as in community-level plans and policies. Most respondent localities reported that using both VMT and LOS at both the project- and plan-level has not created conflicts, indicating that they are able to align VMT and LOS. Mitigation strategies reported as effective in reducing VMT and also improving LOS include improving active...

Enhanced Accounting for Item Cost Variability in AASHTOWare Project Software

Fri, 27 Dec 2024 00:00:00 +0000

This study applies bootstrap analysis to historic transportation project item cost data to develop improved estimates of item costconfidence bounds for use in transportation project cost uncertainty analysis (a component of lifecycle analysis). Bootstrap regression results of confidence bounds will then be integrated into AASHTOWare Project Cost Estimator so that Monte Carlo procedures can estimate project-level confidence intervals for use in lifecycle project cost analysis and transportation capital planning. Data and functions contained within AASHTOWare (a cost estimation software licensed to the Departments of Transportation for over 40 states and the District of Columbia) are employed in the analyses. Coordinating with the Georgia Department of Transportation to obtain a research license for AASHTOWare took longer than expected, resulting in projectdelays. This report summarizes the work completed to date and describes the remaining steps required to finish the study...

Mobility, Energy, and Emissions Impacts of SAEVs to Disadvantaged Communities in California

Sun, 22 Dec 2024 00:00:00 +0000

This study delves into the energy and emissions impacts of Shared Autonomous and Electric Vehicles (SAEVs) on disadvantaged communities in California. It explores the intersection of evolving transportation technologies—electric, autonomous, and shared mobility—and their implications for equity, energy consumption, and emissions. Through high-resolution spatial and temporalanalyses, this research evaluates the distribution of benefits and costs of SAEVs across diverse populations, incorporatingenvironmental justice principles. Our quantitative findings reveal that electrification of the vehicle fleet leads to a 63% to 71% decrease in CO2 emissions even with the current grid mix, and up to 84%-87% under a decarbonized grid with regular charging. The introduction of smart charging further enhances these benefits, resulting in a 93.5% - 95% reduction in CO2 emissions. However, the distribution of these air quality benefits is uneven, with disadvantaged communities experiencing...

Relative Toxicity of Exhaust Particulate After Accelerated Thermal Oxidation of Recycled Vegetable Oil Biodiesel Fuel

Wed, 18 Dec 2024 00:00:00 +0000

Given that today’s real-world diesel fuel supply is comprised of biodiesel as a blendstock with petrodiesel, understanding how addition of biodiesel affects exhaust particle properties and their subsequent effect on human health is critically important. Here, samples of a commercial waste vegetable oil biodiesel B100 fuel were subject to thermal oxidation at 110oC for 5, 10 or 20 hr before diesel engine dynamometer emissions testing as the neat fuel (B100) and as a 20% v/v biodiesel blend (B20) with petrodiesel. Exhaust particulate matter samples collected using impingers were tested for the ability of the particles to initiateformation of reactive oxygen species (ROS) using the abiotic dithiothreitol (DTT) assay. DTT Activity [nmol DTT consumed per minute per mg PM] of three B20, three B100 as well as petrodiesel (B0) fuels over a total of 13 emissions tests with a light-duty diesel engine were compared. Combining data for emissions tests by fuel blend and oxidation status,...

Using Multi-Modal Path-Specific Transit Trips in Transportation Social Sustainability Analysis: Case Study in Atlanta, GA

Mon, 16 Dec 2024 00:00:00 +0000

A previous National Center for Sustainable Transportation (NCST) study examined pandemic-related changes in MARTA transit system service and ridership in Atlanta, GA, and the combined effects on energy use and per-passenger energy use (Fan, et al., 2022). For that previous study, General Transit Feed Specification (GTFS) and the Automated Passenger Counter (APC) datasets were used to develop the transit network and derive distance and passenger load information within the TransitSim analytical framework. The research coupled ridership data with energy use and emission rates from MOVES-Matrix to assess how the changes in transit service and ridership affected energy use and emissions on a per passenger-mile basis. Research performed in this supplemental NCST study improved model algorithms to increase analytical efficiency and to integrate ridership demographics, so that energy use impacts could be assessed across demographic groups for use in social sustainability analysis....

Synthetic Fleet Generation and Vehicle Assignment to Synthetic Households for Regional and Sub-regional Sustainability Analysis

Thu, 5 Dec 2024 00:00:00 +0000

In this study, a modeling framework was developed to generate high-resolution synthetic fleets, for use with synthetic household modeling in activity-based travel models, by integrating various data sources. The synthetic households were generated by pairing household locations and demographic attributes, and synthetic fleets were assigned to the households so that travel demand model outputs would have vehicles associated with each model-predicted tour for energy and emissions analysis. The CO emissions were modeled for each vehicle and each link traversed by vehicles as predicted by the travel demand model, and the results of the synthetic fleet (by employing Monte Carlo simulations and Bootstrap techniques) were compared with those from standard regional and sub-regional fleet configurations. The results demonstrated that using a traditional sub-regional fleet scenario produced 30% higher predicted emissions than when the synthetic fleet was employed with predicted vehicle...

Hyperlocal Monitoring of Traffic-Related Air Pollution to Assess Near-Term Impacts of Sustainable Transportation Interventions

Mon, 2 Dec 2024 00:00:00 +0000

Traffic and air pollution pose significant challenges to environmental sustainability in the South Coast Air Basin, particularly in urban areas like Riverside, California, where major highways contribute to high levels of background air pollution. This study investigates the impact of traffic-related air pollutants, specifically NO2 and PM2.5, in Riverside's Innovation Corridor, a six-mile roadway serving key urban centers and logistics activities. Utilizing a low-cost, measurement-based approach over a one yearperiod, the researchers employed gradient-boosted regression trees to model pollutant concentrations based on traffic and meteorological conditions. Preliminary findings indicate that background PM2.5 and relative humidity are crucial drivers for local PM2.5 levels, while NO2 concentrations are influenced by daily traffic patterns. The study confirms that NO2, a primary pollutant, is closely linked to daily activity, whereas PM2.5 is influenced by regional trends and...

Democratization of Electric Vehicle Charging Infrastructure: Analyzing EV Adoption by Vehicle and Household Characteristics Using Synthetic Populations

Sun, 17 Nov 2024 00:00:00 +0000

The path to transportation decarbonization will rely heavily on electric vehicles (EVs) in the United States. EV diffusion forecasting tools are necessary to predict the impacts of EVs on local energy demand and environmental quality. Few EV adoption models operate at a fine spatial scale and those that do still rely on aggregated demographic information. This adoption model is one of the first attempts to employ a synthetic population to examine EV distribution at a fine spatial and demographic scale. Using a synthetic population at the Census-Tract-level, enriched with household fleet body types and home-charging access, the researchers consider the effect of vehicle body type on EV spatial distribution and home-charging access in California. The project examines two EV body type mixes in a high electrification scenario where 8 million EVs are distributed across 6 million households in California: a “Small Vehicles” scenario where 6 million EVs are passenger cars and 2 million...

Air Travelers’ Ground Transportation Choices at Four Airports in Northern California

Sun, 17 Nov 2024 00:00:00 +0000

Prior studies of travel mode choice in airport ground transportation identified several important relationships between traveler/trip attributes and the selected ground access mode(s). However, those studies did not comprehensively account for qualitative aspects of ground access mode choice, such as general and transportation-specific attitudes and perceptions of mode-specific airport infrastructure. To add insights into air travelers’ ground transportation choices, this study collected a dataset with a survey administered among travelers using four major airports in Northern California in the post-pandemic era.Among the analyses presented in the report, airport ground access mode choice was analyzed, and its relationships with travelers’ socio-demographics, attitudes toward transportation and related topics (e.g., environmental friendliness), and opinions about transportation infrastructure and services (e.g., airport parking fees). The authors identified relationships between...

Exploring Microtransit Adoption and its Impacts on Transportation Access for Underserved Populations

Mon, 4 Nov 2024 00:00:00 +0000

Transportation-disadvantaged populations often face significant challenges in meeting their basic travel needs. Microtransit, a technology-enabled transit mobility solution, has the potential to address these issues by providing on-demand, affordable, and flexible services with multi-passenger vehicles. The ways in which microtransit supports underserved populations and the factors influencing its adoption are not well-studied, however. This research examines SmaRT Ride, a microtransit pilot program in the Sacramento, California, area operated by Sacramento Regional Transit. The project evaluates a broad range of factors influencing microtransit adoption and travel behavior among underserved populations using original revealed choice survey data collected from February – May 2024 with online and intercept surveys. A descriptive analysis revealed that SmaRT Ride has improved transportation access for these communities, complements the transit system by connecting fixed-route...

Smart Charging of Electric Vehicle Fleets: Modeling, Algorithm Development, and Grid Impact Analysis, with Emphasis on Fleets of Transit and Heavy-Duty Freight Vehicles

Mon, 28 Oct 2024 00:00:00 +0000

High charging loads associated with fleets of commercial electric vehicles (EVs) are expected to significantly stress electric power distribution networks, leading to high costs seen by fleet operators. To address these challenges, this report presents a highly flexible smart charging (SC) algorithm for managing EV fleets that arrive and depart from a common depot on a schedule. The algorithm features (i) primary consideration of multiple fleet operator preferences (e.g. minimizing cost, using carbon-free energy), (ii) secondary consideration of grid impact that leverages the existence of multiple optimal (or near-optimal) ways to satisfy fleet operator preferences, and (iii) automatic detection and handling of infeasibility due to large energy demands (characteristic of fleet charging). Provided in this document are two numerical impact assessment studies in which the SC algorithm is shown to be superior to conventional rapid charging, and conventional ‘smart’ charging solutions...

Parameters Driving Concrete Carbonation at its End-of-Life for Direct Air Capture in Transportation Projects

Wed, 16 Oct 2024 00:00:00 +0000

Recent California regulatory efforts, United States goals, and industry roadmaps all target net-zero greenhouse gas (GHG) emissions from the cement and concrete industries within a few decades. While changes in production of cement and concrete, including varying constituents, can greatly reduce GHG emissions, carbon dioxide removal (CDR) will be needed to meet this net-zero goal. Hydrated cement in concrete can carbonate (i.e., form carbon-based minerals with atmospheric CO2) and thus act as a CDR mechanism. This process occurs faster with a large surface area, such as crushed concrete at its end-of-life (EoL), which can be uniquely leveraged by transportation infrastructure projects. In this work, a literature review of key parameters that can facilitate desired CO2 uptake for transportation projects at their end of life is conducted and an initial meta-analyses of data from the literature to inform CO2 uptake for individual projects is performed. Initial considerations for...

Smart Charging of Electric Vehicles: Exploration of Existing Strategies, Modeling, and Grid Impact Analysis Techniques

Thu, 10 Oct 2024 00:00:00 +0000

Electrification of the transportation sector provides the means to significantly reduce greenhouse gas emissions from internal combustion engine vehicles (ICEVs). However, for electric vehicles (EVs) to remain a viable alternative to ICEVs, solutions must be developed to meet the associated growth in power demand (for charging) without stressing the power distribution infrastructure. One potential solution to this challenge is to control the EV charging load through smart charging. The objectives of the proposed research effort are to (i) clearly define the smart charging problem, (ii) complete a comprehensive literature review, (iii) develop and document fundamental models needed to analyze EV charging and grid impact, and (iv) develop mathematical algorithms for solving the smart-charging problem defined in (i).
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Network-wide Emissions Estimation Using the Macroscopic Fundamental Diagram

Mon, 30 Sep 2024 00:00:00 +0000

This report presents a review of the studies incorporating the Macroscopic Fundamental Diagram (MFD) dynamics for emissions estimation using various microscopic estimation frameworks. These studies show the potential of applicability of the MFD-basedtools for emissions estimation. However, the accuracy of existing models in estimating the emissions of large-scale urban networks is questionable due to their inability in capturing the variations in traffic conditions across such networks. As a solution to this problem, we have proposed to develop a multi-reservoir emissions estimation framework by partitioning large-scale networks into smaller regions with homogeneous traffic conditions and low-scatter MFDs like the multi-reservoir Dynamic TrafficAssignment (DTA) models, which can result in more accurate network-wide emissions estimation. The key component of this framework is finding a method to accurately estimate the emissions using aggregated network representation and its...

Results of the 2023-2024 Campus Travel Survey

Sun, 29 Sep 2024 00:00:00 +0000

The UC Davis Campus Travel Survey is an annual survey led by Transportation Services (TS)—formerly known as Transportation and Parking Services (TAPS)—and the National Center for Sustainable Transportation (NCST), part of the Institute of Transportation Studies (ITS) at UC Davis. It collects a rich set of data about travel to the UC Davis campus, demographics, and attitudes toward travel.
The 2023-24 survey collected data from 4,774 people affiliated with UC Davis about their travel to campus during a single week in October and November 2023. It used a stratified random sampling method with the intent to gather a representative sample of the campus population. About 14 percent of those invited responded to this year’s survey. For the statistics presented throughout this report, we weight the responses by campus role (freshman, sophomore, junior, senior, Master’s, PhD, faculty, and staff) and gender so that the proportion of respondents in each group reflects their...

Learning Drivers’ Utility Functions in a Coordinated Freight Routing System Based on Drivers’ Actions

Wed, 18 Sep 2024 00:00:00 +0000

As urban areas grow and city populations expand, traffic congestion has become a significant problem, particularly in regions with substantial truck traffic. This study presents a coordinated freight routing system designed to optimize network utility and reduce congestion through personalized routing guidance and incentive mechanisms. The system customizes incentives and payments for individual drivers based on current traffic conditions and their specific routing preferences. Using a mixed logit model with a linear utility specification, the system captures drivers' route choice behaviors and decisions accurately. Participation is voluntary, ensuring most drivers receive a combined expected utility, including incentives, exceeding their anticipated utility under User Equilibrium (UE). This structure encourages drivers to follow suggested routes. Data collection on drivers' routing choices allows the system to update utility parameter estimates using a hierarchical Bayes estimator,...

American Micromobility Panel (Part 2): Transit Connection, Mode Substitution, and VMT Reduction

Fri, 6 Sep 2024 00:00:00 +0000

This study examined the sustainability of shared micromobility services using data from 48 cities in the US using a 21-day smartphone travel diary and survey data. Population-weighted analysis indicated a much smaller share of transit connection than in prior reported studies, with more reliable data. However methodological decisions could be a cause for such discrepancies suggesting a sensitivity analysis of this same data may be a good next research step. Results also indicated median VMT reduced per micromobility trip to be roughly 0.15 miles for e-scooter share trips and 0.25 miles for bike share (including e-bike) trips. Models of mode substitution confirm prior evidence of factors affecting car substitution including trip distance as the strongest factor. This study also proposed two frameworks for building a sketch planning tool for examining VMT reduction from future micromobility services. This tool could help cities and regions better plan for the micromobility services...

Applying Topological Data Analysis to Logistics Systems Analysis

Wed, 14 Aug 2024 00:00:00 +0000

The purpose of this project is to apply computational tools from topological data analysis (TDA) to study logistical systems suchas freight networks. TDA is a relatively nascent research area that allows one to describe geometric properties of a data set, such as connectivity, existence of holes, or clustering, in a way that imposes minimal assumptions on parametric structures like coordinate systems or forms of probability distributions. In recent years, TDA has been successfully applied to many different scientific domains, such as aviation, path planning, and time series analysis. To the best of the author's knowledge, this project will be the first to apply TDA to the logistics domain.
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Barriers to Reducing the Carbon Footprint of Transportation Part 2: Investigating Evolving Travel Behaviors in the Post-Pandemic Period in California

Mon, 5 Aug 2024 00:00:00 +0000
During the early months of the pandemic, stay-at-home orders and concerns about infection catalyzed a shift toward online activities, such as remote work and e-shopping, resulting in a significant decrease in conventional travel. However, as the effects of the pandemic diminished, the pandemic-induced online activities began to subside, and conventional travel started to rebound. The challenge among transportation planners and policymakers is to determine the lasting effects of the pandemic and adjust the policies accordingly. In the same efforts to understand the evolving travel-related activities and inform policymaking, the 3 Revolutions Future Mobility Program at the University of California, Davis, conducted four waves of mobility surveys between Spring 2020 and Fall 2023. Key findings from the analysis of these data reveal that remote work and a combination of remote work and physical commuting (i.e., hybrid work) emerge as an enduring outcome of the pandemic. The pandemic...

Ideology, Incidence and the Political Economy of Fuel Taxes: Evidence from California 2018 Proposition 6

Sun, 28 Jul 2024 00:00:00 +0000

In 2018, California voters rejected Proposition 6, a ballot initiative that sought to repeal state gasoline taxes and vehicle fees enacted as part of the 2017 Road Repair and Accountability Act. This paper examines the relationship between support for the proposition, political ideology and the economic burdens imposed by the Act. For every hundred dollars of annual per-household costs imposed by the Road Repair and Accountability Act, support for proposition rose by 3–5 percentage points, roughly comparable to a commensurate increase in the share of ”liberal” voters. Notably, the relationship between voting and the economic burden of the policy is seven times strong in the most conservative tracts relative to the most liberal tracts. This heterogeneity has important implications for the popular support for environmental taxes, as conservative areas in California and elsewhere tend to bear a higher burden from transportation and energy taxes than liberal areas.
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To Charge or Not to Charge: Enhancing Electric Vehicle Charging Management with LSTM-based Prediction of Non-Critical Charging Sessions and Renewable Energy Integration

Mon, 10 Jun 2024 00:00:00 +0000

To maximize the greenhouse gas (GHG) emission reduction potential of Battery Electric Vehicles (BEVs), it is critical to develop EV dynamic charging management strategies. These strategies leverage the temporal variability in emissions associated with generated electricity to align EV charging with periods of low-carbon power generation. This study introduces a deep neural network tool to enable BEV drivers to make charging sessions align with the availability of cleaner energy resources. This study leverages a Long Short-Term Memory network to forecast individual BEV vehicle miles traveled (VMT) up to two days ahead, using a year-long dataset of driving and charging patterns from 66 California-based BEVs. Based on the predicted VMT, the model then estimates the vehicle's energy needs and the necessity of a charging session. This allows drivers to charge theirvehicles strategically, prioritizing low-carbon electricity periods without risking incomplete journeys. This framework...

Simulating Bike-Transit Trips Using BikewaySim and TransitSim

Wed, 1 May 2024 00:00:00 +0000

Planners and engineers need to know how to assess the impacts of proposed cycling infrastructure projects, so that projects that have the greatest potential impact on the actual and perceived cycling safety are selected over those that would be less effective. Planners also need to be able to communicate these impacts to decision-makers and the public. This research addresses these problems using the BikewaySim cycling shortest path model. BikewaySim uses link impedance functions to account for link attributes (e.g., presence of a bike lane, steep gradients, the number of lanes) and find the least impedance path for any origin-destination pair. In this project, BikewaySim was used to assess the impacts of using time-only and time with attribute impedances, as well as two proposed cycling infrastructure projects, on 28,392 potential trips for a study area in Atlanta, Georgia. These impacts were visualized through bikesheds, individual routing, and betweenness centrality. Two...

Education as a Key Factor in Policy Support: An Evaluation of National Mileage Fee Support as it Varies with Information and Attitudes

Fri, 5 Apr 2024 00:00:00 +0000

As governing bodies continue to explore mileage fees as an alternative to the gas tax, the uncertainty surrounding public support remains a critical barrier to policy uptake. This study examines the extent to which public perceptions of mileage fees are guided by misinformation or lack of information using a national, internet-based survey. Hypothetical voting opportunities were used to gather respondent support for mileage fees, coupled with educational treatments that address mileage fee fairness, privacy, and costs. The findings indicate that respondents are largely misinformed or lack information about mileage fees and the gas tax. Pre-education, only 32% of respondents supported the policy, but post-education, 46% of respondents supported the policy. Through binomial, multinomial, and fixed effect modeling, we examined the factors associated with policy support, changes in policy support, and the educational treatments. Ultimately, our findings indicate that education...

End of Life EV Battery Policy Simulator: A dynamic systems, mixed-methods approach

Thu, 14 Mar 2024 00:00:00 +0000

Lithium-ion batteries (LIBs) are the enabling technology for modern electric vehicles (EVs), allowing them to reach driving ranges and costs comparable to internal combustion engine vehicles, an important development with EVs being integral to greenhouse gas mitigation efforts. However, LIB advancements include the use of rapidly evolving and chemically diverse batteries as well as larger battery packs, raising concerns about battery production sustainability as well as battery end-of-life (EoL). This study seeks to respond to these concerns by analyzing potential pathways for EoL EV batteries, quantifies flows of retiring EV battery materials, proposes economically and environmentally preferable LIB EoL strategies, and recommends pertinent policies with an emphasis on environmental justice. The researchers used a loosely coupled dynamic systems model that utilized life cycle assessment and material flow analysis and a mixed methods research approach. They find that the U.S....

Stochastic Ridesharing System with Flexible Pickup and Drop-off

Thu, 14 Mar 2024 00:00:00 +0000

Ridesharing can help reduce traffic congestion, greenhouse gas emissions and increase accessibility to transportation in major metropolitan areas across the United States. A robust rideshare system needs to take uncertainties such as traffic congestion and passenger cancellations into account. In this report, the authors propose a data-driven stochastic rideshare system that integrates those sources of uncertainties. Instead of assuming a probability distribution, the approach learns the underlying distribution in travel times and passenger cancellations from historical data. The authors first provide a mathematical model of the problem. Later they propose a stochastic average approximation approach for solving the routing and flexible pickup and drop-off selection problem. They also propose a Branch-and-Price heuristic and Adaptive Large Neighborhood Search-basedmetaheuristic to solve the underlying rideshare routing problem. To validate the approach, the authors construct...

Developing an Efficient Dispatching Strategy to Support Commercial Fleet Electrification

Thu, 14 Mar 2024 00:00:00 +0000

The adoption of battery electric trucks (BETs) as a replacement for diesel trucks has potential to significantly reduce greenhouse gas (GHG) emissions from the freight transportation sector. However, BETs have shorter driving range and lower payload capacity, which need to be taken into account when dispatching them. This paper addresses the energy-efficient dispatching of BET fleets, considering backhauls and time windows. To optimize vehicle utilization, customers are categorized into two groups: linehaul customers requiring deliveries and backhaul customers requiring pickups, where the deliveries need to be made following the last-in-first-out principle. The objective is to determine a set of energy-efficient routes that integrate both linehaul and backhaul customers, while considering factors such as limited driving range, payload capacity of BETs and the possibility of en route recharging. The problem is formulated as a mixed-integer linear programming (MILP) model and...

Integrated Modeling of Electric Vehicle Energy Demand and Regional Electricity Generation

Mon, 29 Jan 2024 00:00:00 +0000

This paper describes a model for developing highly resolved, time-of-day specific electric vehicle charging demand profiles from travel survey data. Since timing of vehicle charging is dependent on electric vehicle supply equipment (EVSE) availability, four EVSE scenarios are considered: 1) home only, 2) home and workplace only, 3) universal EVSE, and 4) a probabilistic scenario where EVSE availability varies by location. To illustrate the implications of differing demand profiles on power grid operation with high renewable generating capacity, the profiles are in a typical regional economic dispatch model. The results provide a valuable approach for understanding the interactions between vehicle electrification and renewable energy deployment while exploring an updated range of assumptions about EVSE availability and charging behaviors for New York and the six New England states. All scenarios result in increased peak demand and increased generation by non-renewable generating...

Coordinated Traffic Flow Control in a Connected Environment

Wed, 17 Jan 2024 00:00:00 +0000

Freeway and arterial transportation networks in most districts are managed separately without any coordination. This lack of coordination increases the severity of traffic congestion when one or both systems reach their capacities. Some field studies have observed reductions in travel time by coordinating freeway ramps with adjacent arterial signals. To advance the investigation, we propose an integrated traffic management strategy that involves variable speed limit, lane change, ramp metering for freeway traffic flow control, and a traffic-responsive signal control scheme for adjacent traffic light intersections.The variable speed limit and lane change control are designed to alleviate congestion at a lane-drop bottleneck in an arbitrary section, and reject potential uncertainties from measurements or model parameters. The ramp metering algorithm takes advantage of the signal plan of neighboring arterial intersection when estimating on-ramp demands. The signal plan for each...

Southern California Transit Training Consortium Online Training in Electrical Systems and Battery Electric Safety Training

Wed, 17 Jan 2024 00:00:00 +0000

In partnership with the Southern California Regional Transit Training Consortium (SCRTTC), the California State University at Long Beach (CSULB) expanded potential audiences and offered program support for the Electric Vehicle Transit Bus High Voltage Safety Awareness class, which was previously developed under the National Center for Sustainable Transportation (NCST). CSULB expanded both the number of online offerings and the geographic reach by opening the class to transit agencies and campus fleet operators within the NCST network. The course was designed to enhance a technician's basic electrical skills and 2-circuit diagnosis, while teaching students how to work with a Digital Volt-Ohm Meter (DVOM). The effort supports the broader goal of building the workforce needed to support the transition to alternative energy and zero emission bus fleets.
View the NCST Project Webpage

If Pooling with a Discount were Available for the Last Solo-Ridehailing Trip, How Much Additional Travel Time Would Users Have Accepted and for Which Types of Trips?

Fri, 12 Jan 2024 00:00:00 +0000

Pooled trips in private vehicles, or pooling, can lead to smaller environmental impacts and more efficient use of the limited roadway capacity, especially during peak hours. However, pooling has not been well adopted in part because of difficulties in coordinating schedules among various travelers and the lack of flexibility to changes in schedules and locations. In the meantime, ridehailing (RH) provides pooled services at a discounted fare (compared to the single-travel-party option) via advanced information and communication technology. This study examines individuals’ preferences for/against pooled RH services using information collected among travelers answering a set of questions related to their last RH trip. In doing so, both trip attributes and rider characteristics are considered. Taste heterogeneity is modeled in a way that assumes the presence of unobserved groups (i.e., latent classes), each with unique preferences, in a given sample of RH riders (N=1,190) recruited...

Emissions and Health Impact of Electric Vehicle Adoption on Disadvantaged Communities

Wed, 3 Jan 2024 00:00:00 +0000

Vehicle electrification has attracted strong policy support in California due to its air quality and climate benefits from adoption. However, it is unclear whether these benefits are equitable across the state’s sensitive populations and socioeconomic groups and whether disadvantaged communities are able to take advantage of the emission savings and associated health benefits of electric vehicle (EV) adoption. In this study, we analyze the statewide health impacts from the reduction of on-road emissions reduction (from reducing gasoline powered cars) and the increase in power plant emissions (from EV charging) across disadvantaged communities (DACs) detected by using the environmental justice screening tool CalEnviroScreen. The results indicate that EV adoption will reduce statewide primary PM2.5 emissions by 24.02-25.05 kilotonnes and CO2 emissions by 1,223-1,255 megatonnes through 2045, and the overall monetized emission-related health benefits from decreased mortality and...

Applying levelized cost of storage methodology to utility-scale second-life lithium-ion battery energy storage systems

Wed, 3 Jan 2024 00:00:00 +0000

The dramatic increase in electric vehicle (EV) sales has led to a rapid increase in deployed lithium-ion battery (LIB) capacity over the last decade. As EV batteries age and are retired from use in vehicles, they will require management. Second-life applications are often proposed as an environmentally and economically preferable management strategy to direct recycling or disposal. In particular, the repurposing of EV LIBs in stationary applications is expected to provide cost-effective solutions for utility-scale energy storage applications. However, the adoption of second-life battery energy storage systems (BESS) has been slow. One barrier to adoption is the lack of meaningful cost estimates of second-life BESS. Thus, this study develops a model for estimating the Levelized Cost of Storage (LCOS) for second-life BESS and develops a harmonized approach to compare second-life BESS and new BESS. This harmonized LCOS methodology predicts second-life BESS costs at 234-278 ($/MWh)...

Evaluating Alternative Strategies for Traffic Reduction in Los Angeles

Tue, 24 Oct 2023 00:00:00 +0000

Traffic congestion is a major problem in large cities worldwide. This project uses high-frequency data from the Los Angeles metropolitan area combined with an instrument that varies spatially and temporally to estimate the causal impact of an additional vehicle mile traveled on travel times. Specifically, the research team exploits the network structure of the Los Angeles highway system and uses crashes on close alternative routes as exogenous shocks to traffic demand. To do so, the team relies on Google Maps to determine the ideal route and alternatives for over 19,000 real-world commutes. The researchers estimate that at peak times an additional trip reduces speed by, on average, 0.22%. They find the optimal toll at peak times is 33 cents per mile, with the toll being lower, even zero, off-peak. The researchers show how this toll varies over space and time, as well as report on its distributional effects. This toll would more than double highway speeds during peak times and...

All Aboard! Easier Transit Travel with Standardized Payments

Fri, 29 Sep 2023 00:00:00 +0000

This study explores interest in, and the challenges faced by transit agencies and operators in the adoption of open-loop payment systems. The research team focuses on the ways that agencies view passenger needs in the context of adopting open payments. Challenges with cash payments, an increasingly cashless society, and the expanding offerings of digital payment options have spurred increased interest in open-loop payments among transit operators. Paying for transit with cash can require additional time at boarding, add extra steps for passengers who must pay with exact fare, and result in service inefficiencies. It presents security concerns for drivers, and administrative burdens for agencies. While the full costs of cash handling vary per agency, the cost of handling and moving cash may be considerable. Pioneering transit agencies are adopting open payment systems that accept credit cards, debit cards, and smartphone/watch-based transactions. However, there is a huge diversity...

Role of Vehicle Technology on Use: Joint analysis of the choice of Plug-in Electric Vehicle ownership and miles traveled

Mon, 25 Sep 2023 00:00:00 +0000

The increasing diversity of vehicle type holdings and growing demand for BEVs and PHEVs have serious policy implications for travel demand and air pollution. Consequently, it is important to accurately predict or estimate the preference for vehicle holdings of households as well as the vehicle miles traveled by vehicle body- and fuel-type to project future VMT changes and mobile source emission levels. Leveraging the 2019 California Vehicle Survey data, this report presents the application of a utility-based model for multiple discreteness that combines multiple vehicle types with usage in an integrated model, specifically the MDCEV model. The model results suggest the important effects of household demographics, residence location, and built environment factors on vehicle body type and powertrain choice and usage. Further the predictions associated with changes inbuilt environment factors like population density can inform the design of land-use and transportation policies...

Evaluating Accessibility of Los Angeles Metropolitan Area Using Data-Driven Time-Dependent Reachability Analysis

Fri, 28 Jul 2023 00:00:00 +0000

This project is to investigate how accessibility of city blocks is quantified through the transport systems and real traffic flow datafrom the Los Angeles Metropolitan Area. The authors investigate the reachability problem and provide a solution with a functional system that is capable of visualizing the reachability map (isochrone). Unlike other studies, this approach is data-driven and does not depend on mathematical graph-theory to compute the isochrone which requires intensive computation. Instead, it focuses on directly processing the large amount of traffic flow data that the Integrated Media Systems Center at USC has collected from the Regional Integration of Intelligent Transportation Systems (RIITS) for more than 10 years under the Center’s existing Archived Traffic Data Management System (ADMS) project. The reachability map construction is based on vehicle trajectories so the researchers devised the Data-Driven Trajectory Generator (DDTG), a data-driven, model-free,...

Hybrid EV and Pure BEV Owners: A Comparative Analysis of Household Demographics, Travel Behavior, and Energy Use

Thu, 27 Jul 2023 00:00:00 +0000

Electric Vehicles (EVs) significantly reduce energy consumption and emissions from on-road operations and help create more sustainable transportation environment by reducing emissions from the entire well-to wheel energy cycle. Differences between hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), and battery electric vehicles (BEV) users is an important element in understanding potential impacts on travel demand and vehicle adoption, the fact that these vehicles may be adopted into households that undertake very different vehicle activities and energy usage patterns has not been a primary focus in the literature. This study differentiates between HEV, PHEV, and BEV users across three factors: owner household socio-demographic attributes, household daily travel patterns, and household energy usage profiles. The analyses examine factors that appear to influence users’ preferences towards specific EV types and how the selection of different EV types potentially...

Local Option Sales Taxes, Metropolitan Planning Organizations, and SB 375: A Question of Priorities

Tue, 25 Jul 2023 00:00:00 +0000

This report considers the role of local option sales taxes (LOSTs) for transportation in influencing spending patterns in regional transportation plans adopted by Metropolitan Planning Organizations (MPOs) in California’s four largest metropolitan regions. Through quantitative analysis of information on LOST measures placed on the ballot from 1976 to 2022, and through case studies of recent LOSTs placed on the ballot in two counties, patterns in LOST expenditure by mode and purpose are compared over time and across regions, and with spending allocated by MPOs in their long-range regional transportation plans.
View the NCST Project Webpage

Results of the 2022-2023 Campus Travel Survey

Tue, 18 Jul 2023 00:00:00 +0000

The UC Davis Campus Travel Survey is an annual survey led by Transportation Services (TS)—formerly known as Transportation and Parking Services (TAPS)—and the National Center for Sustainable Transportation (NCST), part of the Institute of Transportation Studies (ITS) at UC Davis. It collects a rich set of data about travel to the UC Davis campus, demographics, and attitudes toward travel.
The 2022-23 survey collected data from 3,228 people affiliated with UC Davis about their travel to campus during a single week in October 2022. It used a stratified random sampling method with the intent to gather a representative sample of the campus population. About 18 percent of those invited responded to this year’s survey. For the statistics presented throughout this report, we weight the responses by campus role (freshman, sophomore, junior, senior, Master’s, PhD, faculty, and staff) and gender so that the proportion of respondents in each group reflects their proportion...

2022-2023 Campus Travel Survey Summary of Safety and Bike Theft Questions

Tue, 18 Jul 2023 00:00:00 +0000

This report presents some of the key results from the two new blocks of questions included in the 2022-23 Campus Travel Survey. The first block includes questions to assess the safety of pedestrians, bicyclists, and other micro-mobility users. The second block ask respondents questions about incidents related to bike theft and vandalism on campus.
To assess pedestrian safety on campus respondents were asked if they had been hit while walking on campus since the beginning of fall quarter 2022 and if so, to select the mode they were hit by. The set of questions related to fall and crash of bike and micro-mobility users was shown only to respondents who indicated that they were associated with UC Davis during the 2021-22 academic year. The report presents results of questions related to safety of bike and micro-mobility users, including questions on type of fall or crash related incidents, and reasons for their fall or crash while using a particular mode. Respondents...

2022-2023 Campus Travel Survey Brief Report on Commuters’ Perspective about Transportation at UC Davis

Tue, 18 Jul 2023 00:00:00 +0000
This report presents the views expressed by UC Davis commuters related to various issues, challenges, and concerns that they have with the transportation facilities and services in the community in an open-ended question on the 2022-23 UC Davis Campus Travel Survey. The authors analyzed the contents of comments provided by survey respondents and identified common themes to group the comments. Based on this content analysis, they have grouped the views of students and employees across the themes of safety, parking facilities, transportation for people with disabilities, transit issues, biking, challenges with micro-mobility, and EV charging facilities. Only selected comments are included. They present the comments unedited and anonymously, indicating only whether the comment was provided by an Undergraduate Student (U), Graduate Student (G), Faculty (F), Post-Doc (P), or Staff (S).

2022-2023 Campus Travel Survey Telecommuting Trends: Before and After COVID 19 Pandemic

Tue, 18 Jul 2023 00:00:00 +0000

Every year the UC Davis Campus Travel Survey includes questions related to travel to campus during different days in the reference week. Respondents from all role groups indicate how often they travel to the campus during the reference week for school or work. They also indicate the reasons for not coming to work in-person during the same time period. Travel to campus was highly impacted by the COVID-19 pandemic in the 2020-2021 school year as campus switched to remote instruction. In 2021-22, the campus returned to in-person working and instruction which led to increased physical travel. Travel to campus further increased in 2022-23 as more students and staff returned to campus for in-person learning and working.
This report discusses some of the key results from the survey on questions related to physical travel to campus and reasons for no travel to campus before and after COVID-19 pandemic. It presents a comparative analysis of physical travel to campus during...

Slow Streets and Dockless Travel: Using a Natural Experiment for Insight into the Role of Supportive Infrastructure on Non-Motorized Travel

Mon, 17 Jul 2023 00:00:00 +0000

In the early stages of the COVID-19 pandemic, cities across the globe converted street space to non-automobile uses. This project studies four of these slow street programs in the U.S.: in Los Angeles, Portland, Oakland, and San Francisco. In each city, the slow streets (implemented in late spring to early fall 2020) are used as a treatment and compared to non-implemented control groups. The dependent variable is counts of dockless scooter trips passing a mid-block screenline for time periods both before and after slow street implementation. Those dockless scooter counts were obtained from historical data provided by Lime, a dockless scooter provider in each of the study cities. Two methodological approaches were used: differences-in differences (DID) and panel regression analysis with block fixed effects. For the DID analysis, the researchers used networks of candidate slow streets that were not implemented as the control group. Such control networks were available in Los...

Developing a Vehicle Cost Calculator to Promote Electric Vehicle Adoption Among TNC Drivers

Mon, 17 Jul 2023 00:00:00 +0000

This research developed EV Explorer 2.0, an online vehicle cost calculator (VCC) to meet the requirements of transportation network company (TNC) drivers considering acquiring an electric vehicle (EV). The tool was built to also support the needs of other users considering an EV, including other types of gig economy drivers as well as the general population of non-professional drivers. EV Explorer 2.0 includes several important features and functionalities to support the TNC driver use case that are not found in any other available tool: (1) It allows users to estimate TCO for used vehicles as well as new (others only estimate TCO for new vehicles); (2) Outputs include ridehail-driving income estimates, accounting for EV trip bonuses offered by Uber, net driving costs; (3) Estimates of total cost of driving (TCD) include charging network membership fees and charging session fees (in addition to electricity prices). It also includes key features found in other leading tools,...

SB 743 Implementation by Local Governments for Land Use Projects

Mon, 3 Jul 2023 00:00:00 +0000

In 2018, pursuant to Senate Bill (SB) 743 (2013), the Governor’s Office of Planning and Research (OPR) and the California NaturalResources Agency promulgated regulations and technical guidance that eliminated automobile level of service (LOS) as a transportation impact metric for land development projects under the California Environmental Quality Act (CEQA), and replaced it with Vehicle Miles Traveled (VMT). The authors investigated how local governments have been implementing the LOS-to-VMT shift for land development projects, and how that differs from past practice. They also explored whether local governments monitor the actual VMT impacts from completed land use developments and what methods are available to do so. Their findings indicate that all responding jurisdictions acknowledged the mandatory LOS-to-VMT shift, but were in varying stages ofimplementing the shift. For those jurisdictions that had adopted VMT impact significance thresholds, most adhered closely to OPR’s...

Investigating the Temporary and Longer-term Impacts of the COVID-19 Pandemic on Mobility in California

Tue, 27 Jun 2023 00:00:00 +0000

This study investigates how the COVID-19 pandemic has transformed people’s activity-travel patterns, using datasets collected through three waves of surveys in spring 2020, fall 2020, and summer 2021. With this dataset, it was possible to investigate evolving behavioral choices and preferences among respondents at different timepoints: fall 2019 (recollection of the past), spring 2020, fall 2020, summer 2021, and summer 2022 (future expectations). The study highlighted a large shift among California workers from physical commuting to working remotely in 2020, which was followed by a transition towards hybrid work by summer 2021. The shift to remote work and hybrid work varied considerably across population subgroups, and was most popular among higher-income, better-educated individuals, and urban residents. In terms of household vehicle ownership change, those tech-savvy and variety-seeking individuals were more likely to increase or replace household vehicles, while those...

Exploring the Impact of the Federal Tax Credit on the Decision to Lease or Purchase a PEV in California

Fri, 23 Jun 2023 00:00:00 +0000

Using a sample of approximately 7,000 California PEV drivers recruited from California Clean Vehicle Rebate Program applicants, two logistic regression models are specified to analyze responses by PEV lessees and purchasers to the question of what they would do in the absence of the federal tax credit. Possible responses include: purchase/lease the same PEV, switch to a different PEV, switch to a conventional or hybrid (non-plug in) vehicle, or not acquire a vehicle at all. Several key insights are found: higher discounts from the tax credit increase the probability of lessees indicating they would not lease a PEV at all. For purchasers, in addition to not purchasing any vehicle at all, the probability of purchasing a conventional vehicle, or another PEV also increase. These findings could have implications for California’s ability to reach its ZEV milestones and are important to consider due to recent changes to the US federal tax credit. Our findings indicate that many PEV...