published journal article

The Usual Policy Levers Are Not Engaging Consumers in the Transition to Electric Vehicles: A Case of Sacramento, California

Abstract

We investigate whether the population of all vehicle-owning households has already considered purchasing a plug-in hybrid (PHEV) or battery electric vehicle (BEV). First, we explore purchase engagement and find that even in the city where the Zero Emission Vehicle (ZEV) policy originates (Sacramento, California) few consumers are engaged with PEVs, few have considered purchasing one, and many cannot name a single BEV or PHEV presently for sale, and many are not aware of incentives to buy or advertising of them. Next, we model purchase consideration using ordinal logistic models to understand correlations of purchase consideration with awareness of incentives, advertising, or ride and drives; whether respondents know how PHEVs and BEVs are fueled or the name of one for sale, have sought information on PHEVs and BEVs or have spoken to an owner; the density of chargers and PHEVs and BEVs in respondents’ home location; and respondent socio-demographics. We do not find any relationship between common engagement strategies (e.g. advertising, incentives, and ride and drives) and whether consumers have already considered buying a PHEV or BEV. Those who have considered purchasing a BEV or PHEV have done so due to prior interest.

published journal article

Designing Robo-Taxis to Promote Ride-Pooling

Abstract

Robo-taxis (automated vehicles operating in a ride-hailing model) have the potential to improve mobility while reducing traffic, emissions, and energy use. However, such outcomes depend largely on increasing riders per vehicle. Public policy that incentivizes industry to design robo-taxis to support ride-pooling may be critical to achieving positive outcomes. This research reviews current shared automated vehicle designs and literature related to potential consumer risks and benefits of ride-pooling in robo-taxis in order to articulate potential design solutions to promote pooling.

policy brief

Residential Parking Supply Has a Stronger Influence on Household Travel Choices Relative to a Neighborhood’s Walkability and Access to Transit

Abstract

A large volume of research suggests that neighborhood attributes such as public transportation access, residential density, and walkability can have important impacts on people’s travel, carbon footprint, and employment opportunities. More often than not, however, the research conducted on this topic is subject to “self-selection bias.” For example, people who prefer to walk and ride transit are likely to move to neighborhoods that support these choices,while those who prefer to drive instead move to places with nearby highway access and ample parking. To overcome these biases, a research team at the University of California, Santa Cruz surveyed successful applicants to San Francisco’s affordable housing lotteries about their transportation choices and employment. In San Francisco, nearly all new housing developments with ten or more residential units must provide affordable housing units at below-market rates. The units are normally allocated to qualifying households through city-run lotteries. The chances of winning a lottery are small — less than two percent — and so, not surprisingly, households are not selective about which lotteries they enter. Analysis of lottery application data shows that applicants do not appear to enter any particular lottery based on where they would end up living, or if the residence has ample parking, or based onthe neighborhood’s walkability or transit accessibility.

policy brief

A Higher Diesel Tax Increases Road Damage

Abstract

Tractor-trailers dominate the truck cargo industry. Between 1990 and 2010, this industry grew significantly; vehicle miles traveled increased 87 percent and ton-miles increased by 47 percent. While the growth of trucking miles and tonmiles is a positive indicator of economic transformation and expansion, the trucking sector also produces negative externalities, including but not limited to pavement damage. Pavement damage is closely tied to vehicle weight, which is a product of private market decisions driven by the cost of delivery per ton and the frequency of delivery. Understanding the interplay between fuel cost and private sector decisions on truck dispatch (i.e., frequency and load of trucks) is key to understanding infrastructure damage.

policy brief

Lessons Learned from Collaborative Transportation Planning for Sea Level Rise in California

Abstract

Many of California’s critical transportation infrastructure assets along the coast are vulnerable to sea level rise (Figure 1). Climate adaptation generally and sea level rise adaption specifically entail land-use and transportation decisions that affect multiple jurisdictional levels. These decisions involve many stakeholders, including local, regional, county, state and federal agencies, non-governmental organizations, and individual citizens. Adapting transportation infrastructure to sea level rise requires collaboration among these actors. This is a challenging task given that different agencies and stakeholders have different mandates and priorities, which imply different ways of looking at the common issue of adaptation to sea level rise. Researchers at the University of California, Davis examined four case studies of governance processes formed around transportation assets threatened by sea level rise: a state highway along the San Francisco Bay, a coastal highway and railroad in San Diego County, and the Port of Long Beach. The researchers interviewed stakeholders, consulted policy documents, and organized a workshop with agency stakeholders to identify lessons learned and develop practical suggestions for facilitating collaboration to address sea level rise.

white paper

Transportation Access to Health Care During the COVID-19 Pandemic: Trends and Implications for Significant Patient Populations and Health Care Needs

Publication Date

August 1, 2020

Author(s)

Frederick J ZImmerman, Jeffery E Rollman, Katherine Chen, Keith Norris, Kimberley Gregory, Madeline Brozen, Tayler Ward

Abstract

Since March 2020, COVID-19 transportation system disruptions have altered how Americans access routine health care. This report examines current knowledge about disparities in transportation and access to health care for people with various health conditions and healthcare needs. We highlight evidence related to end-stage kidney disease, pregnancy, cancer, mental health and substance use, disabilities, multiple chronic conditions, and preventive care to discuss population-specific transportation needs and challenges, COVID-19 health risks, and impacts of transportation system disruption on health outcomes during the pandemic. The report concludes with policy recommendations for how leaders in transportation, public health, and health care can improve transportation access to care during the COVID-19 pandemic.

policy brief

Handsfree Cellphone Use Has Lingering Negative Effects on Driving Performance

Abstract

Distracted driving is a factor in approximately 3,000 crashrelated fatalities in the United States each year. Studies have shown that the risk of a crash is four to six times greater while using a cell phone, with even higher rates for texting. Despite public warnings and laws, smartphone tasks that require devoted attention, such as texting, emailing, or web browsing, remain common while driving. Most states restrict hands-held cell phone use, including talking and texting, but none have addressed handsfree use, which can also be extremely distracting. Additionally, there is growing evidence that the effects associated with phone use linger beyond the initial loss of attention, known as a “hangover” effect, and are associated with hazardous driving behavior. Researchers at the Schools of Medicine and Engineering at UC San Diego recently concluded an experimental study on driving safety in which 97 participants were asked to perform simulated driving tasks while receiving a handsfree call or short text message. Researchers measured each participant’s driving reactions (i.e., change in speed, amount of swerving, and drifting outside one’s lane), whether they responded to visual cues at the edges of the screen (simulating rear view mirrors), and how much of the road ahead drivers focused on after being distracted.

research report

Influential Factors in the Formation of Partnerships Between Ridehail Companies and Public Transportation

Abstract

In response to the increasing presence of ride-hailing services, namely Uber and Lyft, a growing number of transit agencies have formed partnerships with these and other shared-use mobility companies to offer programs that integrate these services with traditional transit. The programs often start as pilots and typically involve subsidizing ride-hail travel for passengers connecting to public transit routes or traveling at times when public transit offers limited or no service (such as late at night). However, the number of transit agencies forming these partnerships is still small, and transit agencies note concerns over liability and costs, as well as the ability to meet federal standards. Many worry that partnerships may not be a good use of public resources. Transit agencies face a number of service challenges, and partnering with ride-hailing companies likely offers a piece of the puzzle to improving public transit. Future work should expand on this study and focus on the question of long-term funding. Even those partnerships that have had some apparent success may not have fail-safe funds to keep these partnerships and other new models of service such as connecting with bikeshare or other on-demand services.

research report

How the Built Environment Affects Car Ownership and Travel: Evidence from San Francisco Housing Lotteries

Abstract

Credibly identifying how the built environment shapes behavior is empirically challenging because people select residential locations based on differing constraints and preferences for site amenities. The study overcomes these research barriers by leveraging San Francisco’s affordable housing lotteries, which randomly allow specific households to move to specific residences. Using administrative data, the research team demonstrates that lottery-winning households’ baseline preferences are uncorrelated with their allotted residential features such as public transportation accessibility, parking availability, and bicycle infrastructure—meaning that neighborhood attributes and a building’s parking supply are effectively assigned at random. Surveying the households, the team finds that these attributes significantly affect transportation mode choices. Most notably, the research paper shows that essentially random variation in on-site parking availability greatly changes households’ car ownership decisions and driving frequency, with substitution away from public transit. In contrast, the research team finds that parking availability does not affect employment or job mobility. Overall, the evidence from the study robustly supports that local features of the built environment are important determinants of transportation behavior.

policy brief

Asphalt concrete compaction sample specifications