University of California Institute of Transportation Studies

This research synthesis surveys recent literature from 2011 to 2020 on the environmental and economic effects of high-speed rail (HSR) projects from across the globe, with relevant lessons for implementation of the California High-Speed Rail (CAHSR) project. Recent literature shows that—under the right conditions—HSR can lead to both environmental and economic gains across a variety of metrics. To maximize environmental gains, HSR ridership needs to be high, energy propulsion must be powered largely by renewables, and displaced demand for intrastate air travel must not be replaced by longer-haul flights. For there to be economic gains, cities connected by HSR must play complementary roles, rather than competitive ones, within the economy. Otherwise, economic benefits will be consolidated in core cities along HSR routes at the expense of intermediate cities, and efficiencies from agglomeration may lead to an overall decline in employment and economic value added. This synthesis closes with some recommendations for future research questions that can inform the development or refinement of policies that support the successful implementation of CAHSR.