California must build, operate, and maintain transportation infrastructure while ensuring that the health of communities and the planet are not compromised. In addition to vehicleemissions, supply chain inputs and energy use from constructing and maintaining transportation projects (e.g., roads, airports, bridges) result in pollution that contributes to climate change and impacts the health of local communities. Project-specific air and noise pollution can further burden vulnerable populations. By assessing transportation projects using a life-cycle perspective, all relevant emission sources and activities from raw material production, supply chain logistics, construction, operation, maintenance, and end-of-life phases of a project can be analyzed and mitigated.
Reducing air pollution from automobiles is a climate and public health imperative. Transportation is the “single largest source of CO2 emissions” in California and the second largest source nationwide. State leaders recognize the need for zero-emission vehicles to achieve statewide carbon neutrality. Millions of electric vehicles (EVs) are expected on American roads in the coming decade. California alone will require over two million publicly accessible EV chargers to support over 15 million EVs by 2035, and nationwide over 28 million total chargers will be needed by 2030. To date, public charging infrastructure investment has not prioritized lower-income and black and brown communities, and electrification has mostly benefitted higher-income, whiter communities. Federal and state funding programs for charging infrastructure have begun directing vehicle and charging investment to lower-income communities, rural communities, and areas at greatest risk of environmental harm, but this investment must be met with equity-oriented decision-making tools.
While hydrogen fuel-cell electric vehicles (FCEVs) are seen as a part of California’s efforts to decarbonize transportation, especially for the heavy-duty vehicle sector, their role remains unclear. This may change, however, with the launch of the California Alliance for Renewable Clean Energy Hydrogen Energy Systems (ARCHES) developed by the California Governor’s Office of Business and Economic Development (GO-Biz) as a public-private partnership. The U.S. Department of Energy and ARCHES recently signed a $12.6 billion agreement to build a clean, renewable Hydrogen Hub in California, including up to $1.2 billion in federal funding. The transportation sector will play a central role in this effort, including commitments to deploy 6,000 FCEVs, mainly trucks and buses, along with 60 refueling stations and other investments.
The Road Repair and Accountability Act of 2017 (Senate Bill 1 or SB 1) aims to improve and enhance California’s transportation infrastructure. Like many infrastructure programs, however, there are concerns with project cost overruns, delays, and cancellations, as these can undermine program goals and negatively impact quality of life in California. To better understand SB 1 program performance thus far, we analyzed quarterly Caltrans SB 1 project reports between 2018 and 2023 to provide insights into project costs, delays, and cancellations.
Electric vehicles (EVs) are proliferating in California, with over 1.8 million operating in the state. Modern EVs have considerably larger battery packs than early models, in many cases 80-100 kWh for 250-300-mile driving ranges. Charging power for EVs is also increasing. With the appropriate wiring, residential charging at Level 2 has reached up to 19.2 kW though 7-10 kW is more typical, making EVs among the most demanding household power loads. These charging loads can stress local electricity distribution feeders, particularly in the early evening when power use typically peaks.
In this study, we examine if observed line-level changes in OCTA bus boardings could be partly attributed to AB 60, while controlling for differences in transit supply, socioeconomic variables, gas prices, and the built environment. Using fixed effects panel data models, we analyzed monthly boardings on different OCTA route classifications—local, community, Express, and station link routes—one year before (2014) and two years after (2015 and 2016) AB 60’s implementation.
Microtransit is a technology-enabled transit service that typically employs shuttles or vans (Figure 1) to provide on-demand transportation with dynamic routing. While many rides are dispatched and paid via a smartphone, many services also provide a telephone booking option. A few services accept cash payment and street hails (similar to taxis). Variations of microtransit can include fixed schedules and routes and larger or smaller vehicles. Typically, microtransit services are operated by or provided on behalfof a government entity or nonprofit organization, although privately operated microtransit programs also might exist.
To better understand inequities in EV charging costs, we compared charging costs at public EV DCFC stations to the cost for single-family housing (SFH) residents charging at home for three California electric utility service areas, the Sacramento Municipal Utility District (SMUD), San Diego Gas and Electric Company (SDG&E) and Pacific Gas and Electric Company (PG&E), and for three specific urban areas - Sacramento, San Diego, and San Jose. We used a combination of observed pricing data from PlugShare, a crowd-sourced database of public EV charging, and public DCFC pricing data from electric vehicle service provider (EVSP) websites, as well as electric utility tariff information from their respective websites.
During the pandemic, California’s four major rail systems— Bay Area Rapid Transit (BART), San Diego Metropolitan Transit System (MTS), Sacramento Regional Transit (SacRT), and Los Angeles County Metropolitan Transportation Authority (LA Metro)—experienced an average ridership decline of 72 percent between 2019 and 2021. BART had the greatest decrease (87 percent) and MTS the lowest (47 percent). However, ridership changes varied significantly across individual stations, with stations located in the central business district or at the end of lines having the highest ridership losses. Land use, development density, and the pedestrian environment are strongly associated with station-level transit ridership. We examined how these characteristics affect transit ridership pre- and post-COVID and how they differ across station types based on longitudinal data collected between 2019 and 2021 for 242 rail stations belonging to BART, MTS, SacRT, and LA Metro.
More systematic coordination between transportation and housing development is increasingly recognized as a promising strategy for creating more sustainable communities. In California, the importance of transportation-housing coordination is reflected in recent legislative efforts to address the state’s long-standing housing affordability crisis. One approach is to encourage higher density affordable housing developments near transit or in similarly transportation-efficient areas, such as locations with low vehicle miles traveled (VMT). However, little is known about how transportation access should be considered in guiding housing development, what challenges can arise from coordinating housing development with transportation, and what the state can do to better deal with these challenges and achieve more equitable residential densification.
