Recent its_tsc_rw items

Jaywalking in California: History, Pedestrian Safety Trends, Law Enforcement Patterns, and Decriminalization Legislation

Fri, 5 Jun 2026 00:00:00 +0000

This report investigates jaywalking laws in connection with traffic safety, racial equity, and street design, focusing on California. It traces the concept of "jaywalking" to an early 20th-century auto industry campaign to shift safety responsibility from drivers to pedestrians. By analyzing national and California pedestrian injury and fatality data (2009–2022) alongside California Racial and Identity Profiling Act (RIPA) police stop data (2018–2022), the study describes demographic disparities in both pedestrian crashes and law enforcement of jaywalking. It also documents recent legislative efforts in California and other states and cities to decriminalize or reform jaywalking enforcement. Findings show that pedestrian fatalities reached a 40 year high in 2022, with California’s rates consistently exceeding the national average. Significant racial and economic disparities exist: Black pedestrians experience fatality rates multiple times those of White pedestrians, and lower-income...

Vehicle Weight Safety Study Academic Report

Mon, 2 Mar 2026 00:00:00 +0000

The Vehicle Weight Safety Study provides supporting analysis for the California Transportation Commission’s study on therelationship between vehicle weight and road user injury and roadway degradation required by Assembly Bill (AB) 251, which was signed by the Governor in October 2023. To inform the work of the CTC, this report summarizes trends of road user injuries and fatalities in California and potential factors contributing to these trends (Chapter 2); summarizes trends in vehicle weight, size, and height for registered vehicles in California (Chapter 3); documents the landscape of policy solutions focused on vehicle size that might address California’s road user injuries and fatality challenge (Chapter 4); analyzes the impact of potential weight-based fees on consumer vehicle purchasing behavior (Chapter 5); and, analyzes the relationship between shifts in passenger vehicle weight and degradation of road infrastructure (Chapter 6).

A context-sensitive roadway classification framework for speed limit setting in the US

Tue, 16 Sep 2025 00:00:00 +0000

In the US, speed limit setting (SLS) procedures have historically relied on driver-behavior-based methods, such as the 85th percentile speed, which are considered objective and allow for consistent application. However, this approach has notable shortcomings, including drivers’ tendency to underestimate their speeds, speed creep, and insufficient consideration of vulnerable road users, which may conflict with the Safe System Approach and Vision Zero initiatives endorsed by the USDOT (US Department of Transportation). In contrast, context-sensitive approaches, which classify roads based on roadway typologies, have been developed in countries like New Zealand, Sweden, the Netherlands, and Australia. While effective, these approaches have largely been applied outside the US, leaving many US roads with speed limits that may not fit their surroundings or adequately address pedestrian and cyclist safety. Drawing on New Zealand’s One Network Framework, we developed a US-based, context-sensitive...

Creating an Inclusive Bicycle Level of Service: Virtual Bicycle Simulator Study

Fri, 21 Feb 2025 00:00:00 +0000

Bicycle level of service (BLOS) is an essential performance measure for transportation agencies to monitor and prioritize improvements to infrastructure, but existing measures do not capture the nuance of facility differences on the state highway system. However, with the advancements in virtual reality (VR) technology, a VR bicycle simulator is an ideal tool to safely gather user feedback on a variety of bicycling environments and conditions. This research explored the benefits and limitations of using a VR environment to assess individuals’ bike infrastructure preferences. We conducted a bicyclist user experience survey in person on SafeTREC’s VR bicycle simulator and online and compared the results. The online survey consisted of showing participants pairs of VR videos of biking scenarios and asking them to choose the one that they preferred. To validate the online survey responses, we conducted in-person experiments with a VR bike simulator using the same pairs of videos....

Observational Study of Cell Phone and Texting Use Among California Drivers 2015 and Comparison to 2011 through 2014 Data

Wed, 13 Nov 2024 00:00:00 +0000

This methodological and analysis report outlines the procedures and findings for the fifth annual wave of the “Observational Survey of Cell Phone and Texting Use among California Drivers Study, ”conducted by Ewald & Wasserman Research Consultants (E&W) on behalf of the California Office of Traffic Safety (OTS) and the Safe Transportation Research and Education Center (SafeTREC) at the University of California, Berkeley.

Automated Assessment of Safety-Critical Dynamics in Multi-modal Transportation Systems

Wed, 13 Nov 2024 00:00:00 +0000

With the advent of emerging technologies, urban intersections are being increasingly equipped with various types of video-based and in-pavement sensing systems to facilitate round-the-clock monitoring and optimization of multi-modal flows. In comparison, the assessment of the safety performance of these facilities continues to be largely based on either crash history or citizen grievances. Herein lies an opportunity to apply advanced sensing platforms to proactively monitor safety-critical events of multi-modal road users. This work presents a traffic safety monitoring framework which showcases the capabilities of utilizingin-pavement sensors to provide a detailed, automated assessment of mobility and safety-related performance measures for multi-modal traffic at signalized intersections. This effort supplements the crash data-based retrospective studies by routinely monitoring the safety-critical behavior of multimodal traffic. Herein, the term safety-critical refers to...

Safe Routes for Older Adults

Wed, 13 Nov 2024 00:00:00 +0000

Whether rural, suburban or urban dweller, transportation is a critical lifeline to meet the needs of daily living, maintain independence and enable social connection. Walking and bicycling are important transportation alternatives to motor vehicle travel. They are also important sources of physical activity and social connectedness. Creating and/or enhancing environments to be more supportive of walking and bicycling has been a significant initiative within the transportation and health communities for over a decade, with important progress in many locations. Rates of walking and bicycling are up in California, and active transportation policies have become more institutionalized at the state and local level (e.g., Caltrans’ “Toward An Active California State Bicycle/Pedestrian Plan” and the City of Los Angeles Complete Streets Design Guide). With the increased focus on walking and bicycling comes opportunities to improve the safety of the transportation environment...

Classification of bicycle traffic patterns in five North American Cities

Fri, 16 Aug 2024 00:00:00 +0000

This paper analyses bicycle ridership patterns using a unique database of automated bicycle counts from approximately 40 locations in five North American cities and along the Route Verte in Quebec. The cities involved in this study are Montreal, Ottawa, Portland, San Francisco, and Vancouver. Count data show that the bicycle volume patterns at each location can be classified as utilitarian, mixed utilitarian, recreational and mixed recreational. Study locations classified into each of these categories are found to have consistent hourly and weekly traffic patterns, despite important differences between these cities in terms of factors such as weather, size, and urban form. Expansion factors for each location type are presented by hour and day of the week. There were differences in seasonal patterns of bicycle activity between the study locations, so different monthly expansion factors are presented for each city. Finally, some traffic volume characteristics are presented for comparison...

Evaluate the Safety Effects of Adopting a Stop-as-Yield Law for Cyclists in California

Fri, 9 Aug 2024 00:00:00 +0000

The escalating number of injuries and fatalities among cyclists is a pressing safety concern. In the United States, communities are actively seeking strategies to boost cyclist safety, with some states implementing bike-specific policies, such as stop-as-yield laws, to support cyclists. Stop-as-yield laws allow cyclists to treat stop signs as yield signs. The laws are not yet widely implemented, and their potential safety impact is a subject of debate among transportation experts and advocates. This study investigates how stop-as-yield laws can positively or negatively affect safety and provides insights and guidelines for California policymakers and safety practitioners if the law passes in California. We collected cyclist data from five states that have enacted stop-as-yield laws—Idaho, Arkansas, Oregon, Washington and Delaware—and data from some of their contiguous states without such legislation. Using an observational before-after study with comparison groups at the state...

Assessing the Variation of Curbside Safety at the City Block Level

Thu, 1 Dec 2022 00:00:00 +0000

Investigating the dynamics behind the likelihood of vehicle crashes has been a focal research point in the transportationsafety field for many years. However, the abundance of data in today's world generates opportunities for deepercomprehension of the various parameters affecting crash frequency. This study incorporates data from many differentsources including geocoded police-reported crash data, curbside infrastructure data and socio-demographic data for thecity of San Francisco, CA. Findings revealed that the GFMNB model provides a better statistical fit than the FMNB andNB model in terms of AIC and log likelihood, while the NB model outperformed both mixture models in terms of BIC dueto model complexity of the latter. Among the signicant variables, TNC pick-ups/dropoffs and duration of parked vehicleswere positively associated with segment-level crashes.

The Impact of COVID-19 on the Mobility Needs of an Aging Population in Contra Costa County

Mon, 7 Dec 2020 00:00:00 +0000

In 2018, SafeTREC conducted a survey on transportation mobility issues among older adults in California. A follow-up survey planned for 2020, just as the COVID-19 pandemic changed life for all residents, was redesigned to assess mobility needs and changes during the Shelter-in-Place order and focused on COVID-19 impacts. Results indicate that the COVID-19 pandemic and subsequent Shelter-in-Place order have had a major impact on senior mobility. Communications for many were restricted to phone, email, texts, social media and video chats. Among those with a medical problem, just over 60% called a doctor or nurse line or went to a doctor’s office, while 11.2% went to an emergency room, and 8.6% did nothing. A total of 8% of respondents said they had run out of food or other important items during the Shelter-in-Place order. Rates of exercise outside the home dropped 20% between January and June 2020, and while over 60% sought outside entertainment in January 2020, by June 2020, nearly...

Prehospital Response Time and Traumatic Injury—A Review

Tue, 14 May 2019 00:00:00 +0000

A significant proportion of fatalities from motor vehicle collisions (MVC) could be prevented through better emergency medical service (EMS) care. Despite a lack of conclusive research, there is a consensus that prehospital time (the time between the MVC and the patient’s arrival at the hospital) must be reduced as much as possible. Many studies use response time (the time between EMS dispatch and arrival at the scene) as an indicator of overall prehospital time and a metric of EMS performance. However, there are other components of prehospital time that may be equally important, including the discovery time between the collision and EMS notification, the on-scene time, and the transport time from the scene to the hospital. In rural MVCs, the discovery time can be substantial if there are no witnesses or survivors capable of calling emergency services. Technologies that automatically detect MVCs can shorten discovery times in such circumstances. Transport times depend on the distance...

Evaluation of Injury Severity Updates in California Collision Data

Tue, 14 May 2019 00:00:00 +0000

Fatal or injury collisions in California must be reported to the California Highway Patrol (CHP) for inclusion in the Statewide Integrated Traffic Records System (SWITRS). After records have been entered into SWITRS they are made publicly available and are accessible through the CHP’s report and data retrieval site called I-SWITRS. However, records accessed in SWITRS are considered provisional and can be updated several years after initial entry. This includes the injury severity level of collisions. If the collision data was accessed prior to an injury severity update, the agency retrieving the data may unknowingly be working with an outdated version. This can have an impact on government agencies use of data driven safety analyses to apply for safety improvement funding in order to achieve key safety goals in reducing fatal and serious injury collisions. This paper evaluated the frequency and level of injury severity changes for severe injury and fatal collisions that occurred...

Evaluating Research on Data Linkage to Assess Underreporting of Pedestrian and Bicyclist Injury in Police Crash Data

Tue, 14 May 2019 00:00:00 +0000

Traffic safety decisions are based predominantly on information from police collision reports. However, a number of studies suggest that such reports tend to underrepresent bicycle and pedestrian collisions. Underreporting could lead to inaccurate evaluation of crash rates and may under- or overestimate the effects of road safety countermeasures. This review examined ten studies that used data linkage to explore potential underreporting of pedestrian and/or bicyclist injury in police collision reports. Due to variations in definitions of reporting level, periods of study, and study locations, it was difficult to directly compare the studies. Even among the six studies using the hospital link definition, estimates of reporting levels ranged from 44 to 75 percent for pedestrian crashes, and from 7 to 46 percent for bicycle crashes, suggesting a severe underreporting problem. However, few of the studies provided estimates of the error around their reporting level estimates, and as...

Assessing and Addressing the Mobility Needs of an Aging Population

Thu, 9 May 2019 00:00:00 +0000

The mobility needs of an aging population is one of the most substantial challenges facing California in the coming decades. The number of residents age 65 and older is expected to double between 2012 and 2050, and the number age 85 and above is expected to increase by over 70% between 2010 and 2030. Declines in physical function related to age may reduce mobility options dramatically. A survey of 510 residents age 55 and older in Contra Costa County was conducted to determine mobility patterns and limitations related to age and other factors. Results of the survey indicate that a majority of seniors are car dependent. However, some older adults miss important activities due to mobility limitations associated with increasing age, poorer health, living alone, not having a licensed driver in the household, and having a disability. Mobility options are also limited in some geographic areas and demographic groups. Importantly, older adults want to “age in place.” Based on these findings...

Observational Study of Cell Phone and Texting Use Among California Drivers 2012 and Comparison to 2011 Data