National Center for Sustainable Transportation

Finding ways to boost transportation access for underserved populations can unlock broad social benefits. Micromobility programs, including bikesharing, offer scalable solutions. National, state, and regional housing and urban development agencies promote affordable housing and transit-accessible developments by funding programs such as the Low-Income Housing Tax Credit and Community Development Block Grants. However, these efforts are not always coordinated and the physical distance between affordable housing and transit access continues to grow. The problem is compounded by low car ownership rates in lower income urban communities. These circumstances have led to inequitable mobility access. To correct course, pairing affordable housing developments with reliable transit services is essential. This practice can increase equity and accessibility. A team at the University of California, Davis, conducted a case study in Sacramento, California, to explore bikesharing as an option for connecting affordable housing residents with transit services. This brief summarizes the findings from that research and provides implications for the field. 

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Effective policy tools are urgently needed to enable the United States to keep pace with international climate goals. “Feebates”—fees applied to the purchase of vehicles with higher emissions and rebates for clean ones—have become an effective and increasingly common strategy for shaping vehicle markets in European countries. A holistic policy framework that will accelerate the transition to zero emission vehicles (ZEVs) in the US will likely include strong federal policies such as sales mandates, purchase fees for higher emission vehicles, and purchase incentives for ZEVs. Researchers from the University of California, Davis examined what makes a feebate policy work and how this strategy can be leveraged to shift US vehicle markets. The research included a review and analysis of feebate mechanisms in European countries. This policy brief summarizes research findings and provides policy implications.

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Micromobility—including bicycles, electric bicycles, and electric scooters—is well-suited to address first- and last-mile connectivity with public transit by bridging the gaps of service for riders. This extends the geographic region where residents are likely to access and exit a transit station, facilitating access to more jobs, services, and recreation. However, public use of micromobility depends on a variety of factors. These include availability of secure parking facilities or other environmental design features at and around public transit stations. UC Davis researchers and urban design experts considered these issues in a case study of the Bay Area Rapid Transit (BART) heavy rail system. The study included environmental audits at 18 BART stations. The study also hosted an online survey of BART and micromobility users and included interviews with government, industry, and community stakeholders. This policy brief summarizes the findings from this study and provides policy implications.

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Senate Bill (SB) 743 (2013) and its related regulations eliminated automobile level of service (LOS) and replaced it with vehicle miles traveled (VMT) as the primary transportation impact metric for land development projects under the California Environmental Quality Act. Actual implementation of the LOS-to-VMT shift was left up to lead agencies, primarily local governments. The LOS-to-VMT shift was expected to create many challenges, given the often-limited resources of local governments, the entrenched use of LOS, and the perceived lack of established practice regarding VMT estimation, mitigation, and monitoring. With those concerns in mind, researchers at the University of California, Davis investigated how local governments have been implementing the LOS-to-VMT shift for land development projects.  This policy brief summarizes the findings from that investigation.

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In the United States, mileage fees, or road user charges, are being explored as an alternative to motor fuel taxes, often called “gas taxes.” The search for alternatives is motivated by rising fuel efficiency standards and the increasing number of electric vehicles on the road. These factors have diminished the revenue-generating capacity of gas taxes. While mileage fees are a more stable and fuel-agnostic transportation funding source, they face criticism and low levels of public support due to concerns about costs, protection of drivers’ location and privacy, and perceptions that they would raise taxes on low-income and rural households.

Researchers from the University of Vermont Transportation Research Center used data from over 360,000 Vermont vehicles to assess the financial and equity impacts of replacing the Vermont state gas tax with a revenue-neutral mileage fee of 1.5 cents per mile. The researchers then surveyed 623 car drivers in northern New England and 2,114 drivers around the US, before and after offering them an educational experience about mileage fees. The educational experience included videos and quiz-style questions. It covered reasons for a switch to mileage fees, fairness across income and community types, and a personalized cost comparison between the gas tax and mileage fee, based on each respondent’s vehicle and travel information. This brief summarizes the findings from that research and provides implications for the field.

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To reduce greenhouse gas (GHG) emissions from the transportation sector, government programs and regulations are encouraging a transition from internal combustion engine vehicles (ICEVs) to battery electric vehicles (BEVs) and plug-in hybrid electric vehicles (PHEVs), collectively referred to as plug-in electric vehicles (PEVs). California has targets of having 5 million PEVs and Fuel Cell Electric Vehicles on the road by 2030, and 100% of new vehicle sales being zero-emission by 2035. An increasing diversity of vehicle types, paired with a growing demand for PEVs, has major implications for vehicle miles traveled (VMT), air pollution, and emissions. To better understand what is likely to happen,  researchers predict household vehicle preference and VMT by vehicle body and fuel type. This policy brief summarizes the findings from that research and provides policy implications.

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To mitigate climate change and air pollution, multiple US states and other countries have beensetting and adjusting goals and policies aimed at shifting sales from conventional, fossil-fuel–powered vehicles to plug-in electric vehicles (PEVs), defined as plug-in hybrid and battery electric (all-electric) vehicles. For example, US policies have offered federal tax credits for the purchase of PEVs, with limits set on how many PEVs from a single manufacturer, which PEVs, and which consumers qualify. A key to developing or adjusting these policies is understanding how financial incentives affect consumers’ decisions to purchase or lease PEVs. To better understand the impact of financial incentives on PEV leasing and purchasing, researchers at the University of California, Davis, analyzed survey responses from approximately 2,800 California PEV owners. The survey asked: If the federal tax credit were not available would you: purchase or lease the same PEV, switch to a different PEV, switch to a conventional or hybrid (non-plug in) vehicle, or not acquire a vehicle at all? This policy brief discusses findings from those survey responses and provides policy implications.

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In the United States, the transportation sector  is the largest single source of greenhouse gas (GHG) and nitrogen oxide (NOx) emissions, and heavy-duty trucks contribute a disproportionately large share. Therefore, the trucking industry has been seeking ways to minimize emissions, such as adopting zero-emission vehicles and improving truck operating strategies to reduce truck miles. Battery-powered vehicles have different limitations than those with internal combustion engines. In this study, researchers from the University of Southern California investigated the adoption of battery electric heavy-duty trucks (BEHDTs) in the short-haul freight movement sector and the drayage industry. Drayage is a short-haul pickup and delivery service for transporting freight among ports, warehouses, and other facilities. With drayage routing, vehicles have limited weight and volume capacities and often make many stops. Routing involves optimizing for multiple factors, like fuel, distance traveled, and timeliness. This brief summarizes the findings from that research and provides implications for the field.

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California has ambitious climate policy goals, while also facing an acute housing affordability crisis. Transit-oriented development—higher-density residential or mixed-use development centered around high-quality transit stations—has emerged as a strategy to reduce greenhouse gases while increasing housing supply. However, transit-oriented development is more complex and expensive to build than development in low-density, undeveloped areas. State and local governments have adopted numerous policies to encourage transit-oriented development, but little research has examined how various policies can be combined to produce on-the-ground success. Researchers at the University of California, Davis completed in-depth case studies of 11 California cities to understand their mix of strategies and how they have needed to reconcile sometimes competing policy goals in advancing transit-oriented development. This policy brief summarizes the findings from that research and provides policy implications.

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In the early stages of the COVID-19 pandemic, many cities across the US reallocated street spaces for active transportation such as walking, bicycling, and scootering, including by electric bikes and scooters. Slow Streets, projects that limit through-traffic access for motor vehicles to provide a safer space for other travelers, were implemented at an unprecedented speed and scale. This analysis of pandemic-era Slow Street dockless electric scooter (e-scooter) use offers insights that may assist decisionmakers. A research team at the University of Southern California collaborated with Lime, an e-scooter company, to analyze Slow Streets programs in the cities of Oakland, San Francisco, Los Angeles, and Portland. Using two statistical approaches, they examined dockless e-scooter travel at four different times of day and overall weekly and monthly averages of dockless e-scooter trips. This policy brief summarizes the findings from that research and provides policy implications.

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