Health Impact Assessment of Connected and Autonomous Vehicles in San Francisco, Bay Area

Abstract

This paper presents the potential human health impacts from connected and autonomous vehicles (CAVs) in the San Francisco, Bay Area, U.S. The study concentrates on impacts derived from CAVs’ outcomes on travel demand, safety, and environmental emissions. The paper combines travel modeling practices, critical literature review, and the authors’ expert inference, to quantify the human health impacts using the Integrated Transport and Health Impacts Model (ITHIM). Specifically, ITHIM estimates impact considering changes in travel demand, level of physical activity, emissions, and safety features. This study estimates a 10% increase in car travel mileage and an 11% decrease in walk/bike trip mode share at the presence of CAVs; a 70%–90% crash reduction because of safer CAVs; and significant emission reduction by several CAV-enabled mechanisms such as eco-driving (over 30% CO2 emission reduction) and engine performance adjustment (over 20% CO2 emission reduction). The health impact assessments show significant opportunities for road traffic injury reductions (annual saving of more than 300 deaths and 14,000 life years). However, reduced physical activity because of the mode shift to the car could cause negative health outcomes (increased annual deaths and disability-adjusted life years (DALYs) by more than 30–60 and 700–900, respectively). A set of (active transport [AT] and vehicle electrification) scenarios were developed that could mitigate the potential health-related risks and evaluated their effectiveness. The results show enormous benefits from 50% increased travel-related physical activity which offset the CAV health drawbacks and generates additional benefits by preventing premature deaths and saving life years.