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on Transport Economics |
| By: | Shaheen, Susan PhD; Martin, Elliot PhD; Ju, Mengying |
| Abstract: | Transportation network companies (TNCs), also known as ridehailing, such as Uber and Lyft, have contributed to increased vehicle miles traveled (VMT) and associated emissions in California’s urban areas over the past decade. In response, Senate Bill (SB) 1014 – the Clean Miles Standard – requires TNCs to achieve 90% electric vehicle (EV) miles traveled and zero greenhouse gas (GHG) emissions per passenger mile by 2030. The California Public Utilities Commission (CPUC) and the California Air Resources Board (CARB) oversee implementation and enforcement of these targets. |
| Keywords: | Engineering |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt2jm242h7 |
| By: | Herbert-Faulkner, Rowland Awadagin PhD; Macfarlane, Jane PhD; Frick, Karen Trapenberg PhD; Walker, Joan PhD |
| Abstract: | This policy brief presents a network analysis method that is accessible to local and regional transportation agencies using Mobiliti, a high-performance traffic simulator currently available for research purposes. However, we demonstrate Mobiliti’s practical applications for transportation agencies. Developed by research scientists at Lawrence Berkeley National Lab, Mobiliti offers traffic assignment solutions and regional simulation capabilities, allowing for high-resolution, iterative exploration of road treatments and routing strategies. Analysts can manipulate network characteristics and vehicle behavior by adjusting parameters such as lane count, speed limit, and the percentage of vehicles, to dynamically optimize travel times. These capabilities can support transportation equity evaluations by giving network managers deeper insights into the mutual relationships between local and regional traffic dynamics and the resulting social impacts. |
| Keywords: | Engineering |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt1bh4k6n5 |
| By: | Gonzales, Marta C. PhD; Ozturk, Ayse Tugba |
| Abstract: | Despite the years of climate change mitigation effort, per capita transportation emissions are on the rise. Reducing vehicle miles traveled, congestion mitigation and increasing vehicle efficiency are three strategies to reduce CO2 emissions from vehicles. Outcomes of these strategies may contradict each other considering their impacts on the road network and possible behavior changes within the transportation system. Though, models used in policy evaluations do not capture the interplay between vehicle characteristics, travel demand, and urban form. Understanding the spatial and temporal variations in vehicular emissions and the impact of each subsector requires collaboration between two seemingly separate fields: emissions modeling and urban science. |
| Keywords: | Engineering |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt4dk29637 |
| By: | Ferguson, Beth; Blandino, Jordan Scott |
| Abstract: | This study investigates the evolution of shared micromobility vehicle design and safety practices in the San Francisco Bay Area from 2017 to 2024. Shared micromobility includes e-bikes and e-scooters. Stakeholder interviews revealed that limited protected bike lanes, poorly designed or neglected e-bike and e-scooter fleets, deteriorating road infrastructure, and unsafe rider behavior have impeded the widespread adoption of shared micromobility in urban areas. There is a pressing need for consistent design standards for lighting, battery charging, braking systems, vehicle frames, and wheel sizing to further improve safety and vehicle durability. Recommendations include expanding protected bike lanes, improving road maintenance, offering e-bike riding lessons, promoting helmet use, and encouraging substance-free riding. Enhancing vehicle security and implementing battery safety protocols are also critical for improving charging accessibility and reducing theft and fire risks. |
| Keywords: | Engineering, Shared mobility, Micromobility, Electric bicycles, Scooters, Electric vehicles, Traffic safety, Bicycle facilities, Batteries, Interviews |
| Date: | 2025–10–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt1nb7s2jn |
| By: | Ding, Kaijing; Hansen, Mark PhD |
| Abstract: | This study provides a method to quantify the benefits of reducing the costs from flight delays by shifting air passenger traffic to high-speed rail (HSR). We first estimate the number of flight reductions by each quarter hour for airport origin and destination pairs based on HSR ridership forecasts in the California High-Speed Rail 2020 Business Plan. Lasso models are then applied to estimate the impact of the reduced queuing delay at SFO, LAX and SAN airports on arrival delays at national Core 29 airports. Finally, these delay reductions are monetized using aircraft operating costs per hour and the value of passenger time per hour. We apply several different variations of this approach, for example, considering delay at all 29 Core airports or just major California airports, different scenarios for future airport capacity and flight schedules, and different forecasts for future HSR ridership. We estimate mid-range delay cost savings of $51-88 million (2018 dollars) in 2029 and $235-392 million (2018 dollars) in 2033. The estimated savings are similar to, but slightly lower than, those based on cost estimates to upgrade airport capacity to handle passenger traffic that could be diverted to HSR. |
| Keywords: | Engineering, High speed rail, air travel, ridership, forecasting, mathematical models, flight delays, mathematical models, airport capacity, railroad capacity, cost analysis |
| Date: | 2025–10–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt8g57g791 |
| By: | Steren, Aviv PhD; Tal, Gil PhD; Robinson, Anya R. |
| Abstract: | Class 2b-3 vehicles, bridging the gap between light-duty and heavy-duty trucks, represent a critical yet underexplored segment in California’s decarbonization efforts. These medium-duty vehicles, weighing 8, 501-14, 000 lbs., play diverse roles across personal and commercial sectors but remain behind in electrification compared to other vehicle classes. This study provides a comprehensive assessment of Class 2b-3 vehicle ownership, usage patterns, and electrification potential in California, leveraging county-level registration data, household and commercial vehicle surveys, and qualitative interviews. Findings reveal significant geographic, socio-economic, and operational disparities: rural and lower-income counties exhibit higher concentrations of Class 2b-3 vehicles, while electric vehicle (EV) adoption – driven mainly by lighter vehicle classes – remains concentrated in urban, high-income areas. Commercial vehicles in this class demonstrate higher mileage and lower fuel efficiency than standard commercial vehicles, amplifying their emissions impact. Despite these challenges, policy initiatives such as California’s Hybrid and Zero-Emission Truck and Bus Voucher Incentive Project (HVIP) and emerging vehicle technologies signal pathways for electrification. However, barriers persist, including high upfront costs, range requirements, and infrastructure gaps. The study indicates that targeted interventions, especially in rural areas, and flexible technology solutions are essential to accelerate electrification and ensure equitable clean transportation access across California. |
| Keywords: | Engineering, Decarbonization, Electric vehicles, Medium trucks, Vehicle range, Commercial vehicles, Technology adoption, Rural areas, Transportation equity |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt4gc0j900 |
| By: | Robinson, Anya R.; Hardman, Scott PhD |
| Abstract: | In California, 38% of greenhouse gas (GHG) emissions come from the transport sector, and 27% of these transport emissions come from passenger vehicles. To reach carbon neutrality by 2045, as directed under Executive Order B 55 18, electrification of passenger vehicles is required. To facilitate an equitable transition to electric vehicle technologies, policymakers must account for the diverse needs and challenges faced by residents in rural communities. Rural areas often have greater travel distances and a reliance on passenger vehicles, due to a lack of alternative modes. While rural areas account for only 7% of the state’s population, California policy decisions can be far reaching and serve as guidance for other states with higher rural populations. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt1hf1z1qj |
| By: | Li, Yanning PhD; Jenn, Alan PhD |
| Abstract: | California leads the nation in a shift to electric vehicles (EVs), with ambitious targets for phasing out the sale of new gas-power cars by 2035. However, this transition raises serious concerns about whether the state’s electrical grid can handle the surge in charging demand. Without careful planning, grid infrastructure limitations and the associated costly upgrades could become a major bottleneck to widespread EV adoption. To better understand this challenge, we simulated EV charging profiles (i.e., how, when, and where EVs are charged) across different types of locations across California, including homes, workplaces, and public charging stations. We then evaluated the impact on the state’s electrical distribution system. Our findings point to where and when the grid is most vulnerable—and what policies can help balance EV growth with grid stability. |
| Keywords: | Engineering |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt7j7026p8 |
| By: | Steren, Aviv PhD; Tal, Gil PhD; Robinson, Anya R. |
| Abstract: | Medium-duty trucks in the Class 2b-3 range (8, 501-14, 000 lbs.) are a critical and overlooked segment in California’s vehicle market. These trucks—used as work vehicles, delivery vans, and large personal-use pickups—are disproportionately owned and used in rural and lower-income communities. While they make up a relatively small share of the overall truck fleet in California, they contribute disproportionately to fuel use and emissions due to their high annual mileage and low fuel efficiency. Electrification of these vehicles has lagged far behind both passenger cars and heavier commercial trucks. According to the California Air Resources Board’s EMFAC model, battery electric vehicles (BEVs) account for just 1.5% of Class 2b and 0.2% of Class 3 vehicles in California, compared to 6.9% of passenger vehicles. This gap reflects both technical barriers (e.g., range, payload, or towing capacity)3 and policy gaps, since many incentive and regulatory programs focus on fleet-owned, heavier Class 4-8 trucks or exclude consumer-owned pickups altogether. Additionally, Class 2b-3 vehicles, often classified differently in household vs. commercial datasets, has made it difficult to understand who owns them, how they’re used, or where the best opportunities for electrification lie. |
| Keywords: | Engineering |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt28g0s1r9 |
| By: | Kurani, Kenneth S.; Nordhoff, Sina; Hardman, Scott |
| Abstract: | Meeting and sustaining a requirement that 100 percent of new passenger vehicle and light-duty truck sales be zero emission vehicles (ZEVs) requires everyone who acquires a new vehicle to only acquire ZEVs. This puts an onus on understanding resistance to ZEVs: who is resistant and why. These questions are addressed using survey data from repeated cross-sectional samples of all-car buying households in California in the years 2017, 2019, and 2021. Concepts of resistance are introduced and provisionally mapped onto Consideration, a multidimensional assessment of what consumers have already done vis-à-vis two types of ZEVs: battery and fuel cell electric vehicles (BEVs and FCEVs). Results indicate that active consumer resistance did not abate for BEVs over the study period, and that while it did abate slightly for FCEVs the probability of active resistance became less dependent on assessments of FCEV performance, fuel availability, or comparisons to conventional gasoline-fueled vehicles. Resistance based in political beliefs is extended from ZEVs to thepolicy requiring ZEVs using data from an additional survey of car-owning households in California from late 2023 to early 2024. The attitude that cost and convenience matter more in daily decisions than do environmental effects has a strong influence on the likeliness of disagreeing with the ZEV sales requirement. Conceptual shortcomings are noted in the mapping of resistance onto Consideration which limit the usefulness of Consideration as proxy for resistances going forward as is the lack direct measures of political affiliation in the extension to resistance to policy. A comprehensive set of suggestions to improve the direct measurement of different forms of resistance is provided. View the NCST Project Webpage |
| Keywords: | Social and Behavioral Sciences, Attitudes, Automobile ownership, Consumer preferences, Electric vehicles, Fuel cell vehicles, Surveys |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt2zz6v9zk |
| By: | Gonzales, Marta C. PhD |
| Abstract: | Plug-in electric vehicles (PEVs) are among the most promising strategies for reducing transportation-related emissions and mitigating their impacts on both the environment and public health. Historically, PEV adoption has been slowed by three key barriers: range anxiety, limited charger availability, and high purchase costs. Recent advances — including improvements in battery technology, tax incentives, and subsidized charging programs — have begun to ease these challenges, leading to steadily increasing adoption rates. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt1b5132h1 |
| By: | Jaller, Miguel |
| Abstract: | The advent of e-commerce has changed consumer behavior and brought about a growing last-mile delivery system. These deliveries provide consumers with access to goods and services that would otherwise require personal trips to brick-and-mortar locations or not be available. To improve the efficiency of last-mile delivery and mitigate potential effects on traffic, communities, and the environment, e-retailers are trying out a diverse set of distribution strategies. These include: (1) using light-duty vehicles such as electric vans and cargo bikes in conjunction with micro-hubs, consolidation centers, and staging areas to reduce heavy traffic and operational costs; (2) establishing collection points (e.g., parcel lockers) that allow customers to pick up their orders at convenient locations, without the need for additional delivery vehicle travel; (3) engaging independent drivers who can provide flexible and cost-effective delivery, (4) deploying autonomous delivery robots and unmanned aerial vehicles; and (5) replacing conventional fuel vehicle fleets with zero- or near-zero emissions vehicles. A team at the University of California, Davis explored the economic viability, environmental efficiency, and social equity impacts of these strategies with state of the art modeling techniques. |
| Keywords: | Engineering |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt82d1r9cs |
| By: | Zhang, Michael PhD; Gao, Hang; Qi, Yanlin |
| Abstract: | High occupancy vehicle (HOV) lanes allow carpool vehicles to bypass congestion and save travel time. However, HOV lanes are often underutilized, leading to a waste of road capacity or the loss of travel time advantage over general purpose lanes. To address this issue, high-occupancy toll (HOT) lanes have gained popularity. HOT lanes, when properly priced, preserve the advantage of HOV lanes, while allowing single-occupant vehicles to pay for access, making use of spare HOT lane capacity. |
| Keywords: | Engineering |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt8fq3446x |
| By: | Jenn, Alamn PhD |
| Abstract: | The gasoline tax, the primary source of transportation funding in California and United States, is rapidly losing effectiveness as vehicles become more fuel efficient and as electric vehicles enter the market. To address this funding shortfall, many states are exploring alternatives to the gas tax such as a road usage charge (RUC), which charge drivers based on miles traveled rather than fuel consumed. The 2021 federal Infrastructure Investment and Jobs Act (IIJA) supports this transition by funding both national and state-level RUC pilot demonstrations. Despite growing momentum, questions remain about how RUCs affect equity. Policymakers are particularly concerned about whether rural residents, who often travel longer distances, or disadvantaged communities, who already face economic and mobility barriers, would be disproportionately burdened. To better understand these impacts, my team examined how a revenue-neutral RUC in California would change the financial burden of switching from a gas tax to RUC, focusing on geographic and community differences. |
| Keywords: | Engineering |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt35z4p34f |
| By: | Bhuiya, Md Musfiqur Rahman; Barajas, Jesus M. PhD; Venkataram, Prashanth S. PhD |
| Abstract: | Traffic safety remains a pressing concern in California. Over the past five years, the state has averaged more than 3, 751 reported traffic fatalities annually, with likely more unreported. While policies and research often focus on crash prevention and severity reduction, less is known about how collisions affect individuals’ travel behavior and perceptions of road safety. To better understand these effects, we conducted interviews and focus groups with people who had direct or indirect experience with traffic collisions and near misses. We also spoke with professionals who support collision victims, such as physicians, therapists, faith leaders, and advocacy groups representatives. Discussions focused on perceptions of road safety, transportation mode choices, and travel behavior of someone involved in a traffic collision or near miss before and after the incident. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt3dh2s5gj |
| By: | Jenn, Alan PhD |
| Abstract: | This report examines the differences in what drivers would pay with a gasoline tax versus a revenue-neutral road user charge (RUC) and whether these differences are equitably distributed among rural vs. urban and disadvantaged vs. non-disadvantaged communities. The analysis uses vehicle registration data from the California Department of Motor Vehicles, vehicle attribute data from DataOne, and environmental and socioeconomic indicators from CalEnviroScreen. On average, a transition from a gas tax to an RUC would cause drivers in rural areas to pay less per mile and drivers in urban areas to pay more. This difference arises because vehicles registered in rural areas tend to have lower fuel efficiency than those in urban areas. However, the transition from gas tax to RUC would have a similar impact on average cost per mile for vehicles registered in disadvantaged communities (defined as the top 10% of census tracts in CalEnviroScreen) as in other communities.. This study indicates that RUCs are marginally less regressive than gas taxes. |
| Keywords: | Engineering, Mileage-based user fees, Fuel taxes, Transportation equity, Rural areas, Underserved communities |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt9375t56r |
| By: | Peterson, Lisa; Nguyen Vo, Karen |
| Abstract: | The UC Berkeley Safe Transportation Research and Education Center (SafeTREC) has released the California Traffic Safety Survey 2025. The study was led by Ewald & Wasserman Research Consultants (E&W) and conducted on behalf of the California Office of Traffic Safety (OTS) and SafeTREC. The California Traffic Safety Survey has been conducted annually since 2010 to gain a better understanding of a range of traffic safety behaviors and to help inform traffic safety programs and public education campaigns. This year’s survey was conducted with an online panel of California drivers in all California counties for a total of 2, 319 respondents, with the majority of those surveyed (59.1% unweighted) coming from Southern California and falling within the 18-44 age range. Over 25 questions were created to address a variety of topics concerning road safety, including distracted driving, driving under the influence of alcohol and drugs, pedestrian and bicyclist safety, statewide safety campaigns, and driverless vehicles. First introduced to the California Traffic Safety Survey in 2022, respondents were also asked to rate five elements of increasing road safety that comprise the Safe System Approach. |
| Keywords: | Social and Behavioral Sciences, traffic safety, distracted driving, driving under the influence, pedestrian safety, bicyclist safety, driverless vehicles |
| Date: | 2025–09–30 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt95g4w441 |
| By: | Pike, Susan; Affolter, Bailey; Smith, Nina Bonelli; Lipatova, Liubov |
| Abstract: | Since the beginning of the twenty-first century, young people have become a considerable share of public transit users. However, younger representatives of this age group still face many barriers to access transit infrastructure and benefit from its service. This study examines a Youth Cruz Free program launched by the Santa Cruz METRO in March 2023, allowing kids and teenagers of school age to use the service for free. The researchers were interested in understanding how the program has changed the travel behavior of teenagers, whether it encourages adolescents to use the service after they turn 18, and what factors influence their overall ridership of Santa Cruz METRO. To reach both current high school students and recent graduates, the researchers completed two rounds of surveys distributed among high schools in Santa Cruz County. The surveys asked about adolescents’ sociodemographics, the availability of different modes of transportation, school attendance, and other variables that might change patterns in their mobility and encourage/discourage transit adoption. After completing multiple statistical tests, the researchers identified the factors impacting teenagers’ travel behavior. Hispanic/Latinx students were found to ride the METRO more frequently than White students. Students with a driver’s license and students with higher numbers of household vehicles are less likely to use public transportation. Perceptions of safety also correlate significantly with youth ridership. Surprisingly, variables such as gender, job frequency, and the walking distance from the bus stop were not significantly related to bus use frequency. While additional research could aim to better target all riders, including communities of color and those in rural areas, the findings support the growing literature on youth ridership and fare free programs. The results suggest perceptions of safety are worth addressing at a systemic level, and that public transit becomes less desirable once individuals have access to personal vehicles and licenses. View the NCST Project Webpage |
| Keywords: | Social and Behavioral Sciences, Bus transit, Demographics, Free fares, High school students, Ridership, Surveys, Travel behavior |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt3qh42308 |
| By: | Comandon, Andre; Boarnet, Marlon |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt1nf7t9r2 |
| By: | Atkins, Jon; Baverman, Michelle; DaCosta, Ameen; Hurtado, Alyssa |
| Abstract: | Oakland, California’s road network contains some of the most dangerous streets in the San Francisco Bay Area. In 2022, 36 people died in traffic incidents in the city, with pedestrians and bicyclists making up half of all fatalities. Crashes in Oakland disproportionately occur in the city’s Equity Priority Communities and along its High Injury Network, and across the region, Alameda County has one of the highest rates of pedestrian fatalities. Oakland’s roadways are also home to nearly 100 slip lanes: separated, one-way right-turn lanes designed to improve traffic flow. While slip lanes enable drivers to make smoother and faster turns, they prioritize vehicle speed and efficiency and increase the risk of pedestrian collisions at intersections. This report documents the locations and existing conditions of 94 slip lanes in the City of Oakland. We find that one-third of all slip lanes in Oakland are located along the city’s High Injury Network, with just over half (52%) located in Equity Priority Communities. We then examine the inequitable distribution of safety infrastructure that puts pedestrians, communities of color, seniors, and low-income residents at higher risk of traffic injury. We find that 75% of slip lanes do not have crosswalks, and nearly 90% of slip lanes do not have pedestrian crossing signals. Since 2014, 592 traffic collisions have occurred at intersections with slip lanes, resulting in 806 injuries. We assume the lack of safe pedestrian crossings may be contributing to increased traffic risks and collision outcomes. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–02–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt2fc4n5s5 |
| By: | Li, Yanning PhD; Jenn, Alan PhD |
| Abstract: | California’s rapid shift toward vehicle electrification will require substantial upgrades to the state’s electricity distribution grid (i.e., the part of the electric power system that delivers electricity from substations to homes, businesses, and other end users). Without proactive planning, these upgrades risk exacerbating existing inequities in access to electric vehicle (EV) charging infrastructure and grid capacity. Specifically, disadvantaged communities that already struggle with higher pollution and economic hardship have lower rates of EV adoption, but are more likely to need costly grid upgrades to support charging. To better understand these equity implications, we analyzed grid capacity and charging needs across more than 5, 000 distribution feeders in California. We combined real-world utility data with projections of EV adoption and charging behavior models for light-, medium-, and heavy-duty vehicles. |
| Keywords: | Engineering |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt5vx8c2h0 |
| By: | Fitch-Polse, Dillon; Nakafuji, Alana |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Engineering, Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt3302s4j4 |
| By: | Fernández-Bonilla, Fernando; Ruíz-Rúa, Aurora; Gijón, Covadonga; Martínez de Ibarreta Zorita, Carlos |
| Abstract: | Touristic mobility is a major contributor to greenhouse gas emissions, particularly due to the dominance of private vehicle. This study explores the determinants of sustainable transport choices among domestic tourists in Spain, focusing on how individual, territorial, and digital factors influence the adoption of public and low-emission transport modes. Using the Resident Tourism Survey (INE, 2016–2024), we estimate logistic and ordered regression models that incorporate sociodemographic variables, trip characteristics, and e-tourism indicators. Results reveal a strong association between digital planning and sustainable modal choice, particularly in urban and coastal destinations. Additionally, cultural and educational travel activities are more likely to be linked to public transport use, while leisure activities show a higher dependence on private modes. Socioeconomic factors like income, education, and age also significantly affect transport behaviour. This research highlights the need for territorialised, integrated policies to promote sustainable mobility in tourism, especially in rural areas. Enhancing digitalisation, improving public transport access, and tailoring strategies to specific regional and profiles are key to enabling a greener transition in tourism mobility. |
| Keywords: | e-Tourism, Rural, e-Mobility, Sustainability, Logit Model |
| Date: | 2025 |
| URL: | https://d.repec.org/n?u=RePEc:zbw:itse25:331268 |
| By: | Handy, Susan; Hosseinzade, Rey |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewedacademic literature and has detailed discussions of study selection and methodological issues.VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt59d7j674 |
| By: | Comandon, Andre; Boarnet, Marlon G. |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt8pm9q4xs |
| By: | Robinson, Anya; Konstantinou, Theodora PhD; Tal, Gil PhD |
| Abstract: | Little is known about plug-in electric vehicle (PEV) ownership, charging behavior, and vehicle characteristics in rural California. As the state works toward its goal of carbon neutrality by 2045, understanding the current state of PEV adoption in rural areas is essential for identifying where targeted support may be needed to meet electrification objectives. Existing definitions of “rural” may also obscure important variation within these regions. This study proposes a passenger-vehicle-based classification of rural areas in the state using k-means clustering, incorporating data on land use, travel behavior, vehicle characteristics, and housing attributes. Five distinct clusters were identified, three of which - Rural Remote, Farm Rural, and Small Town - were classified as rural. Survey data from PEV and conventional vehicle (CV) owners were analyzed to compare sociodemographic characteristics, vehicle attributes, and charging access and behavior. Across all clusters, PEVs were newer and generally smaller than CVs. The Rural Remote cluster exhibited the highest rural PEV adoption rates (1.4% BEVs, 1.0% PHEVs), along with higher household income, education, and Level 2 home charging prevalence. Farm Rural and Small Town clusters had lower adoption rates and relied more heavily on Level 1 charging, despite comparable at-home charging frequency. Public charging access per capita was lowest in Rural Remote areas and highest in Small Town clusters across rural areas. These findings indicate that rural California is heterogeneous with respect to PEV ownership and future adoption potential. Policies that account for demographic, infrastructural, and travel behavior differences between rural subtypes may be more effective than uniform approaches in supporting adoption. |
| Keywords: | Social and Behavioral Sciences, Rural areas, Electric vehicles, Electric vehicle charging, Automobile ownership, Demographics, Cluster analysis |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt2kk0g5w1 |
| By: | Lin, Rui PhD; Wang, Pei PhD |
| Abstract: | Onboard eco-driving systems provide drivers with real-time information about their driving behavior and road conditions, encouraging them to optimize their driving speed and consequently reduce fuel consumption and emissions. However, there are barriers to making eco-driving a habit. To determine the elements that influence drivers’ intentions to practice eco-driving and their acceptance of eco-driving technology, we developed a theoretical model based on established theories on planned behavior, technology acceptance, and personal goals. The findings showed that drivers’ intention to practice eco-driving has an indirect effect on their intention to use the system via the factor of perceived ease of use. We also explored how cognitive distraction while using an eco-driving system can be a potential barrier to acceptance. The intent is to put forward a solution to improve drivers’ usage eco-driving by turning off guidance when the system detects that the driver is experience from serious distraction. To investigate how to detect a driver’s cognitive distraction status when they are interacting with an eco-driving system, we used a driving simulator and leveraged machine learning algorithms to classify drivers’ attentional states. The findings showed that the glance features played a more important role than the driving features in cognitive distraction. |
| Keywords: | Engineering, Eco-driving, connected vehicles, fuel consumption, traffic safety, mathematical models, driver performance, behavior, eye fixations, cognition, driving simulators |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt1cc649wh |
| By: | Fitch-Polse, Dillon; Fukushige, Tatsuya |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewedacademic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (orother measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt5q1665f4 |
| By: | Fixler, Noelani; Ekunno, Melie |
| Abstract: | While recent California legislative reforms grant jurisdictions greater flexibility to lower speed limits, evidence suggests that reductions in posted speed limits alone are insufficient to meaningfully reduce crash severity. This research brief examines how speed limit reductions, when paired with infrastructure design, enforcement strategies, and contextual land-use planning, can more effectively lower FSI outcomes. Aligned with the Safe System Approach, the countermeasure layers of roadway geometry, lighting, bicycle-specific infrastructure, and enforcement shape driver behavior and protect vulnerable road users. This approach provides a pathway for communities to advance vulnerable road user safety by reducing speeds through a holistic approach. |
| Keywords: | Social and Behavioral Sciences, speed limit, fatal and serious injury, California, crashes |
| Date: | 2025–07–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt38b4b3p6 |
| By: | Baverman, Michelle |
| Abstract: | This study examines the relationship between transit-oriented development (TOD), gentrification, and commuting behavior in the San Francisco Bay Area from 1990 to 2023. TOD has been promoted as a strategy to reduce automobile dependence and greenhouse gas emissions by concentrating housing and jobs near high-quality transit. Critics, however, argue that TOD may accelerate gentrification and displacement, reducing transit ridership if higher-income households replace transit-dependent residents. Using decennial Census data (1990, 2000) and American Community Survey estimates (2010–2023), all standardized to 2010 block group geographies, I constructed a Baseline Vulnerability Index to identify neighborhoods susceptible to gentrification and a Gentrification Change Index to measure shifts in demographic, income, education, and housing over time. These measures were linked to changes in commute mode shares to assess whether neighborhood change near TOD has influenced transit and car commuting. Findings indicate that TOD station areas gentrified more rapidly than other neighborhoods: 34% of vulnerable block groups in station areas gentrified between 1990 and 2019, compared with 26% in one-mile buffer zones and 20% beyond one mile. Gentrifying TOD neighborhoods also demonstrated a disproportionate increase in new transit commuters between 2010 and 2019. However, post-2020 data reveal sharper declines in transit commuting and modest increases in car commuting in gentrifying TODs, reflecting the impact of remote work and differences in how higher- and lower-income households use transit. The results suggest that while TOD-related gentrification may support transit commuting in some contexts, in a post-COVID world, it poses risks for long-term equity outcomes and overall ridership resilience. |
| Keywords: | Social and Behavioral Sciences, Transit oriented development, gentrification, displacement, commuting, mode choice, low income groups, upper income groups |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt9bt7x4xx |
| By: | Handy, Susan; Hosseinzade, Rey |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt2z48k56p |
| By: | Fitch-Polse, Dillon; Hung, Elena |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt0sk2v1vf |
| By: | Herbert-Faulkner, Rowland A. PhD; Macfarlane, Jane PhD; Frick, Karen T. PhD; Walker, Joan L. PhD |
| Abstract: | This report explores how local DOTs can leverage advanced traffic modeling software to narrow the gap between their network management authority and their analytical capacity. Limited computational and analytical capacity among local DOTs has historically made detailed on-demand analytics inaccessible. Using the Mobiliti traffic simulation platform, we examine the City of San José's Safer Streets program to determine the operational and social impacts of the city’s traffic management strategies. We find that imposing a 20 mph speed limit cap on residential streets in San José’s Equity Priority Communities leads to a 39% reduction in passthrough traffic on those streets, but a 76% increase in traffic on streets in the surrounding network. Using this analytical approach, instead of relying on technical assistance from MPOs network managers can more quickly gain quantified insights into the response of network dynamics to localized interventions. |
| Keywords: | Social and Behavioral Sciences, (Traffic simulations, Advanced traffic management systems, Transportation equity, Speed limits, Traffic volumes, Network analysis (Planning)) |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt3cr711sz |
| By: | Chatman, Daniel G.; Rodynansky, Seva; Boarnet, Marlon; Comandon, Andre; Snyder, Breitling; Patel, Kieran; Atkins, Jon |
| Abstract: | Do affordable housing projects in high-quality transit-oriented development areas reduce auto use? By how much? Under what conditions? These questions are complex but highly relevant for the state of California. Its Affordable Housing and Sustainable Communities (AHSC) program estimates reductions in vehicle miles traveled (VMT) associated with project applications, and scores applications partly on this basis. Building on a large set of existing empirical literature, we carried out a new analysis of how the built environment affects travel in California. We relied on several data sources including movement data from cell phones purchased from a private firm; travel diary data from the 2017 National Household Travel Survey (the most recent household travel survey for the state); data on housing characteristics and commuting from the 2017 American Housing Survey; and neighborhood, community, and regional built environment and public transportation data from Federal and local sources. Consistent with previous literature, we did not find evidence that parcel-level characteristics influenced auto use, but our study reinforced the evidence in existing empirical literature about the importance of larger-scale built environment factors influencing VMT, from the scale of the Census block group up to the radius of a 45-minute drive from home. We recommend that the AHSC calculator be modified to take these factors into account, in addition to including the availability of off-street parking, when calculating VMT reductions. We also recommend that the calculator use a counterfactual assumption about alternative development locations using our quantitative estimates and based on a more appropriate spatial scale. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–08–15 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt99j4s0bp |
| By: | Comandon, Andre; Boarnet, Marlon G. |
| Abstract: | This project reviews and summarizes empirical evidence for a selection of transportation and land use policies, infrastructure investments, demand management programs, and pricing policies for reducing vehicle miles traveled (VMT) and greenhouse gas (GHG) emissions. The project explicitly considers social equity (fairness that accounts for differences in opportunity) and justice (equity of social systems) for the strategies and their outcomes. Each brief identifies the best available evidence in the peer-reviewed academic literature and has detailed discussions of study selection and methodological issues. VMT and GHG emissions reduction is shown by effect size, defined as the amount of change in VMT (or other measures of travel behavior) per unit of the strategy, e.g., a unit increase in density. Effect sizes can be used to predict the outcome of a proposed policy or strategy. They can be in absolute terms (e.g., VMT reduced), but are more commonly in relative terms (e.g., percent VMT reduced). Relative effect sizes are often reported as the percent change in the outcome divided by the percent change in the strategy, also called an elasticity. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt5tt078qv |
| By: | Gulhare, Siddhartha; Makino, Keita; Roshan, Ranbir; Circella, Giovanni |
| Abstract: | California sets ambitious climate goals that demand a sharp reduction in the per-capita vehicle miles traveled (VMT). Traditionally, researchers have relied on three types of VMT data collection methods – travel surveys, passively collected data, and simulated data – to estimate VMT or understand factors affecting VMT. However, each of these methods has disadvantages for obtaining a reliable VMT dataset. Although travel surveys are an inexpensive way to collect VMT data with rich traveler attributes, they often suffer from bias and errors in reporting or recalling. Passively collected VMT data, such as traffic count data, can provide precise VMT data, yet they often lack information about “who” and “why” of travel. Lastly, simulated VMT data is useful when making counterfactual testing, but they are after all not real data. In this study, to fulfill the gap between current data collection strategies, the authors introduce a WhatsApp-based VMT data collection framework. The framework deployed on the Azure cloud platform automatically lets study participants submit photos of their odometer, communicates with them for administrative events, manages submitted images and other information of the participants, and displays that data on the web UI for the study administrator. With a pilot study with 77 participants, the authors successfully collected 173 photos of the odometer. Although only 3 photos out of 173 were unusable, demonstrating the capability of the framework, a couple of potential improvements, such as an interface that aligns the photo timestamps over the days or better recruitment approaches, should be addressed in future work. View the NCST Project Webpage |
| Keywords: | Social and Behavioral Sciences, Data collection, Mobile applications, Odometers, Photographs, Pilot studies, Vehicle miles of travel |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt201603jv |
| By: | Harold, Brian; Rodier, Caroline PhD; Sanguinetti, Angela PhD; D'Agostino, Mollie C. |
| Abstract: | Many Californians face “transportation poverty”–a lack of reliable, efficient, safe, and affordable ways to get to jobs, school, shopping, and medical appointments. Universal Basic Mobility (UBM) programs aim to close this gap. One approach is providing income-qualified individuals with mobility wallets (e.g., prepaid debit cards) used to cover costs for a range of transportation services and options, such as shared mobility and transit services. The range of transportation choices available to mobility wallet participants often helps reduce reliance on personal vehicles while supporting cleaner, lower-carbon travel. To understand how these programs work in practice, we evaluated UBM pilots in four California cities– Los Angeles, Bakersfield, Oakland, and Stockton–and reviewed similar efforts across the country. Our research highlights design features, challenges, outcomes that matter most for agencies and policymakers considering this new tool for addressing transportation barriers. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt0ts6g50w |
| By: | Blodgett, Kyler |
| Abstract: | This research brief offers an early analysis of California’s rollout of speed safety camera pilot programs under Assembly Bill 645 (AB 645). No California city has ever had an automated speed camera program before Spring 2025. Documenting the program set-up and early administration experience of the pilot cities will be informative in advancing road safety efforts if speed cameras become more widespread across the state. After examining research on speed camera effectiveness and best practices based on a review of national programs, the brief focuses on Oakland and San Francisco. Drawing on interviews with city staff, the brief evaluates how well California’s approach aligns with best practices in effectiveness and equity. It finds that AB 645 incorporated many instructive learnings from elsewhere, including income-based fine reductions and data-driven site selection. It also identifies areas for further improvement such as public transparency, alternatives to monetary penalties, approach to infrastructure investments, and enforcement challenges. The brief concludes that, depending on program improvements in these areas, speed safety cameras could become a valuable tool in California’s efforts to reduce traffic-related injuries and fatalities without exacerbating social inequities. |
| Keywords: | Social and Behavioral Sciences, speed camera, California, AB 645, traffic safety, Oakland, San Francisco |
| Date: | 2025–04–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt98r16803 |
| By: | Acey, Charisma PhD; Lin, Margaretta; Pinigis, Alex; Lindheim, Dan PhD; Herbert-Faulkner, Roland Awadagin PhD |
| Abstract: | Top-down transportation planning practices have historically ignored the needs and concerns of low-income communities of color, which can lead to residential and commercial displacement as public investments increase land values and rents. The concept of mobility justice centers the needs of communities that have historically been excluded from transportation planning decisions. We partnered with community groups to examine two transportation planning projects in the Bay Area using collaborative research methods. The first was a retrospective analysis of the East Bay Bus Rapid Transit project in East Oakland that reflects the harms of top-down planning. The second study examined the City of Richmond’s Transformative Climate Communities projects, a more collaborative approach to planning with low-income communities involved at every stage. We find that the top-down planning model employed in the East Oakland case study resulted in significant health, safety, and displacement impacts that could have been avoided. The Richmond case study shows project changes occurring as a direct result of using mobility justice principles. |
| Keywords: | Social and Behavioral Sciences, Transportation planning, Transportation equity, Underserved communities, Low income groups, Sustainable transportation, Public health |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt5154d2hd |
| By: | UC Berkeley SafeTREC |
| Abstract: | In the summer of 2025, the UC Berkeley Safe Transportation Research and Education Center (SafeTREC) conducted a Needs Assessment to explore the need for, and interest in, a program to support and nurture California communities’ road safety work to align with an effective Safe System Approach. As part of the Assessment, interviews and surveys were conducted, finding strong interest in such assistance, particularly for peer learning, leadership support opportunities, and more concrete examples of successes to inform individual communities’ work. |
| Keywords: | Social and Behavioral Sciences, Safe System Approach, road safety, traffic deaths, needs assessment |
| Date: | 2025–09–30 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt37b6g9wt |
| By: | Li, Jia PhD; Qi, Yanlin; Zhang, Michael PhD |
| Abstract: | Emerging machine learning capabilities can be leveraged to make transportation infrastructure safer and reduce fatalities by informing decisions about which countermeasures to apply at crash-prone locations. At this time, project prioritization typically involves assessing effectiveness, cost-benefit ratios, and available funding. Crash Modification Factors (CMFs) play an essential role in project assessment by predicting the effectiveness of safety countermeasures. Their applicability has limitations, however. Some of these may be overcome with innovative approaches such as knowledge-mining. |
| Keywords: | Engineering |
| Date: | 2025–08–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt0x26t67j |
| By: | Zhou, Rui; Fulton, Lewis |
| Abstract: | This paper compares global transportation/energy models in terms of scope, structure and the types of scenarios that have been developed, with particular emphasis on projections of low-carbon fuels like hydrogen, biofuels, e-fuels and electricity in transportation decarbonization scenarios. Our review of the models and their scenarios indicates that scenarios with deep CO2 reduction or globally ambitious climate policies tend to show a large increase in the role of electrification, advanced biofuels and in some cases hydrogen in transport energy by 2050 and/or later years. Different transport modes and sectors have different requirements and are projected to adopt different low-carbon fuels. Electricity is projected to play a key role in road and rail, though liquid low-carbon fuels dominate shipping and aviation and are expected to eventually surpass petroleum use. Deep CO2 reduction scenarios tend to assume strong policies that drive reductions. Policies such as efficiency standards, technology requirements, achieving technological innovation, and infrastructure investment are typically important drivers for influencing the adoption and scale-up of low-carbon technologies and fuels across regions. |
| Keywords: | Engineering, Social and Behavioral Sciences |
| Date: | 2025–10–02 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt490159fh |
| By: | Anthony Wiskich |
| Abstract: | This paper examines how autonomy affects the competitiveness and operations of battery-electric long-haul trucks. We model fleet operations between Sydney and Melbourne-Australia's busiest long-haul corridor-using a parameterised cost-minimisation framework. By lowering travel-time costs, autonomy leads to slower optimal speeds and reduced energy use. This enables smaller, lighter battery packs or reduces the number of charging stops en route, lowering total costs. Autonomy thus enhances the economic case for battery-electric trucks, improving their cost competitiveness relative to diesel trucks to approximately the same extent as would a AUS$50/kWh reduction in battery pack price. |
| Keywords: | heavy-duty trucks, overland freight, economics, autonomous vehicles, decarbonization |
| JEL: | O33 Q40 Q54 R40 |
| Date: | 2025–12 |
| URL: | https://d.repec.org/n?u=RePEc:een:camaaa:2025-65 |
| By: | Pike, Susan PhD; Matute, Juan; Reginald, Monisha; Saphores, Jean-Daniel PhD |
| Abstract: | Open-loop payments systems allow riders to pay fares using general-purpose payment methods like credit cards, debit cards, or mobile wallets (Apple Pay, Google Pay), rather than being limited to a single transit agency’s own payment system. Broad adoption of open-loop payments offers major benefits for public transit, including lower costs, greater convenience for riders, and improved operational efficiency. The California Integrated Travel Project (Cal-ITP) has helped pave the way for transit agencies interested in this technology by providing resources, guidance, and hands-on support. Cal-ITP works directly with transit agencies to address known challenges and identify solutions to emerging barriers. Understanding how agencies decide whether to adopt open-loop and other technologies is key to ensuring the effectiveness of programs like Cal-ITP. To explore this, we surveyed transit agencies in California to identify the factors that influence adoption of open-loop payments. |
| Keywords: | Engineering |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt0xk7v8g8 |
| By: | Hsu, Cheng-Kai; Tsao, Melody; Moran, Marcel E; Griswold, Julia B; Schneider, Robert J; Bigham, John M |
| Abstract: | In the US, speed limit setting (SLS) procedures have historically relied on driver-behavior-based methods, such as the 85th percentile speed, which are considered objective and allow for consistent application. However, this approach has notable shortcomings, including drivers’ tendency to underestimate their speeds, speed creep, and insufficient consideration of vulnerable road users, which may conflict with the Safe System Approach and Vision Zero initiatives endorsed by the USDOT (US Department of Transportation). In contrast, context-sensitive approaches, which classify roads based on roadway typologies, have been developed in countries like New Zealand, Sweden, the Netherlands, and Australia. While effective, these approaches have largely been applied outside the US, leaving many US roads with speed limits that may not fit their surroundings or adequately address pedestrian and cyclist safety. Drawing on New Zealand’s One Network Framework, we developed a US-based, context-sensitive roadway classification framework for urban and suburban areas that incorporates “Place, ” which captures surrounding land uses and locational contexts, and “Movement, ” which relates to the road’s transport function. Using nationally available data from the Smart Location Database (SLD) and the Highway Performance Monitoring System (HPMS), we evaluated our roadway classification framework through internal reviews by our research team and external interviews with state-level practitioners, uncovering both opportunities and challenges in adopting a context-sensitive SLS approach in the US. Our findings demonstrate the feasibility of creating an objective context-sensitive roadway classification in the US and offer insights for developing new speed-limit guidance aligned with the Safe System framework. |
| Keywords: | Engineering, Social and Behavioral Sciences, Speed management, Speed limit setting, Context-sensitive, Roadway classification, Safe System Approach, Place and movement, United States |
| Date: | 2025–09–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt3xd0k23j |
| By: | Dhole, Anuj; Fulton, Lewis; Hwang, Roland; Segall, Craig |
| Abstract: | Zero emission trucks are on the verge of rapid adoption in California due to strong regulatory and incentive support, but recent actions at the federal level threaten to stall progress. To achieve the next phase of widespread commercialization, California must take further action to ensure that ZETs are affordable, abundant, and accessible to all businesses. Continuation of purchase incentives is critical to the success of the ZET market, given the current high upfront purchase cost. ITS-Davis has analyzed the design of a zero-emission truck (ZET) incentive program that could help re-design or supplement the current Clean Truck and Bus Voucher Program (HVIP) and continue to provide certainty for fleet buyers to transition, given the recently withdrawn Advanced Clean Fleets (ACF) regulation for trucks and federal actions that could weaken or delay implementation of the Advanced Clean Truck (ACT) regulation. Our analysis shows that a 10-year time-limited incentive program designed to achieve the ACT sales targets would cost about $4.34 billion1, 2. With long-term funding certainty and transparency on rebate levels, manufacturers that envisage a large volume ZET production would have a strong incentive to competitively price their trucks. California has already invested over $6 billion in incentives for the ZET transition and with additional funding and policy support, could help ensure the state reaps the health and economic benefits of its past investments in the ZET transition. |
| Keywords: | Engineering, Social and Behavioral Sciences |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsdav:qt6zt5110c |
| By: | Ekunno, Melie; Gorostieta, Lilette; Leckie, Kris |
| Abstract: | Bicycling provides youth with mobility, independence, and opportunities for physical activity, but head injuries remain a leading risk of biking-related crashes. Helmets are among the most effective tools for preventing serious injury, yet rates of consistent use among children and adolescents remain low and unevenly distributed across demographic groups. This paper reviews evidence on the social, cultural, and structural factors shaping helmet use and examines the role of school-based programs in promoting safer biking practices. Findings indicate that free and subsidized helmet distribution reduces access barriers but requires reinforcement through education and community engagement to sustain long-term use. Safe Routes to School initiatives improve safety and normalize active transportation, while educational campaigns influence knowledge, attitudes, and peer norms, particularly when combined with parental involvement. Equity concerns, including affordability, enforcement, and cultural compatibility, remain central to program design. Overall, the evidence highlights the need for integrated, equity-focused, and sustainable approaches to increase helmet adoption and reduce preventable injuries among young bicyclists. |
| Keywords: | Social and Behavioral Sciences, head injuries, helmet, cycling, Safe Routes to School |
| Date: | 2025–07–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt4489j561 |
| By: | Acey, Charisma PhD; Lin, Margaretta |
| Abstract: | Top-down transportation planning practices have historically ignored the needs and concerns of low-income communities of color. Federal funding guidelines, agency objectives, regional and local planning processes, and community priorities often conflict with each other at the expense of the health, safety, and livelihood of vulnerable populations. Decades of discriminatory government policies and disinvestment have enabled gentrification, particularly in underserved neighborhoods where new transportation investments make these areas more accessible and attractive to wealthier, often white, residents, which can lead to residential and commercial displacement as public investments increase land values and rents. Mobility justice, which treats mobility as a fundamental human right and promotes a version of transportation planning that incorporates distributive, procedural, and recognition justice, offers an alternative framework. |
| Keywords: | Social and Behavioral Sciences |
| Date: | 2025–11–01 |
| URL: | https://d.repec.org/n?u=RePEc:cdl:itsrrp:qt2zr0p7r2 |