policy brief

Clean Air in Cities: Impacts of the Layout of Buildings in Urban Areas on Pedestrian Exposure to Traffic-Related Pollutants

policy brief

Electric Bike-share in the Sacramento Region is Replacing Car Trips and Supporting More Favorable Attitudes Towards Bicycling

Abstract

Bike-share services have rapidly expanded in cities worldwide and attracted substantial ridership, especially as electric and dockless bike- and scooter-share services have entered the market. These services have the potential to offer a healthier and more environmentally sustainable mobility option if used as an alternative to car travel and a connection to transit. However, little is known about the influence of bike-share systems on individual travel behavior; particularly if bike-share trips are replacing vehicle trips and increasing transit use. To address this knowledge gap, researchers at the University of California, Davis surveyed Sacramento-area residents before and after the 2018 implementation of a JUMP/Uberoperated dockless electric bike-share program to examine how the micromobility service influenced general travel behavior and attitudes. Surveys were sent to residents in downtown Sacramento, West Sacramento, and Davis within the bike-share service area and to a control group in Sacramento outside the service area. Key findings from the research are summarized in this brief.

dissertation, thesis, or capstone

Changing Plans: Flexibility, Accountability, and Oversight of Local Option Sales Tax Measure Implementation in California

policy brief

Upzoning Under SB 50: The Influence of Local Conditions on the Potential for New Supply

Abstract

In this brief, the researchers explore what might happen were SB 50 to pass by taking a detailed look at local market conditions in four case study neighborhoods. Local context shapes financial and physical feasibility. When SB 827, the predecessor to SB 50, was under consideration, estimates of its impact on new housing supply were optimistic. Yet, most of these estimates focused on aggregate development potential and did not consider the on-the-ground reality of other zoning provisions that may influence development, what types of projects might pencil out, or what the existing stock looks like.

policy brief

Drivers of Partially Automated Vehicles are Making More Trips and Traveling Longer Distances

Abstract

Consumers are purchasing and using partially automated vehicles, yet little research has been conducted to understand how and if these vehicles are changing travel behavior. Fully automated, or driverless, vehicles are receiving much more research and policy attention but are still many years from market introduction. Research on fully automated vehicles has shown that, without proper policies in place, these vehicles could increase vehicle miles travelled (VMT). Tesla vehicle models with the ‘Autopilot’ feature are some of the most common partially automated vehicles on the road today. A partially automated vehicle provides advanced driver assistance by controlling steering, acceleration/ deceleration, and braking; however, the human driver is still considered to be in control of the vehicle and is expected to be attentive. A previous UC Davis study found that Tesla vehicle owners with the Autopilot feature drove more than those without Autopilot, but the study did not determine whether higher VMT was caused by Autopilot. To better understand whether Autopilot influences how much individuals drive, the UC Davis research team interviewed 36 Tesla Autopilot users to evaluate whether they experienced changes to their travel, and the reasons for any reported changes. Key findings from the interviews are presented in this brief.

policy brief

E-commerce is Reshaping the Warehousing Landscape – and it May Impact Disadvantaged Communities

Abstract

Prior to the last decade, the logistics industry trended towards the development of mega-warehouse facilities in suburban settings far from core markets, creating a phenomenon known as logistics sprawl. This trend is particularly prominent in Southern California (Figure 1). Since the 2008-2009 economic crisis, however, the trend has shifted. The rise of e-commerce may have influenced supply chain decisions to locate warehouses and distribution centers closer to denser urban areas to enable faster deliveries to consumers. The changes in size and spatial distribution of warehouses and distribution centers as well as the environmental and equity implications of these changes are not fully understood. As warehouses and distribution centers locate in denser urban areas, they may introduce additional diesel truck traffic into disadvantaged and low-income communities.To gain a better understanding of how the spatial distribution and size of freight facilities are changing and the implications of these changes for disadvantaged and low-income communities, researchers at the University of California, Davis analyzed aggregate data about the number of warehouses and distribution centers and disaggregate real estate data of purchases and leases during the last three decades in California. They also analyzed the relationship between freight facilities and communities of concern using the California Environmental Protection Agency’s CalEnviroScreen 3.0 tool. The research focused on the San Diego, Los Angeles, San Francisco, San Joaquin Valley, and Sacramento regions. Key findings from the research are presented in this brief.

policy brief

Shared Autonomous Mobility Services Show Promise for Increasing Access to Employment in Southern California

Abstract

Workers in Southern California currently face transportation related challenges accessing employment opportunities, including but not limited to high parking costs and/or limited parking availability in dense employment and residential areas; long commute distances between residential areas and employment opportunities; and poor transit service quality in many areas. These challenges are particularly burdensome for low-income households that may not have access to a personal vehicle and/or live in job-poor neighborhoods, as having a personal vehicle may be the only viable way to get to work.

research report

Assessment of the Employment Accessibility Benefits of Shared Autonomous Mobility Services

Abstract

The goal of this study is to assess and quantify the potential employment accessibility benefits of Shared Autonomous Mobility Service (SAMS) commute modes across a large diverse metropolitan region considering heterogeneity in the working population. To meet this goal, this study employs a welfare-based (i.e. log sum-based) measure of accessibility, obtained via estimating a hierarchical work destination-commute mode choice model. The employment accessibility log sum measure incorporates the spatial distribution of worker residences and employment opportunities, the attributes of the available commute modes, and the characteristics of individual workers. This research further captures the heterogeneity of workers using latent class analysis (LCA). The latent class analysis model inputs include the socio-demographic characteristics of workers to subsequently account for different worker clusters valuing different types of employment opportunities differently. The accessibility analysis results indicate: (i) the accessibility benefit differences across latent classes are modest but young workers and low-income workers do see higher benefits than high- and middle-income workers; (ii) there are substantial spatial differences in accessibility benefits with workers living in lower density areas benefiting more than workers living in high-density areas; (iii) nearly all the accessibility benefits come from the SAMS-only mode as opposed to the SAMS+Transit mode; and (iv) the SAMS cost per mile assumption significantly impacts the magnitude of the overall employment accessibility benefits.