Institute of Transportation Studies at UC Berkeley

Airports play a critical role in emergency response and disaster recovery, yet are highly vulnerable to earthquakes. Past earthquakes in California, including the 1989 Loma Prieta, 1994 Northridge, and 2014 South Napa events, caused infrastructure damage, power outages, and operational delays at airports, affecting both safety and mobility. As seismic risk remains high across the state, improving airport resilience is critical to maintaining transportation access and supporting emergency operations.Earthquake Early Warning (EEW) systems offer a way to reduce these risks by providing seconds to tens of seconds of advance notice before strong shaking begins. While this technology has been around for several decades across the world, the development of the ShakeAlert system has brought it to the West Coast recently, giving airports in the region the chance to be early adopters of the technology in the United States. To better understand how EEW could be used in airport settings, we examined its operational applications, benefits, and implementation challenges across different types of airports.

Earthquakes pose a persistent and significant threat to the movement of people, goods, and services. While agencies have made progress on emergency response, planning for recovery (how quickly transportation systems can be restored after a major event) remains limited. A key challenge is that earthquake modeling and transportation system modeling have remained largely separate efforts, making it difficult for agencies to anticipate disruptions, prioritize investments, and coordinate recovery across jurisdictions.

As California transitions to electric vehicles (EVs), ensuring equitable access to public charging remains a challenge. While the state and utilities have invested heavily in new charging infrastructure, simply counting stations does not show whether the network is reliable, affordable, and accessible, particularly for vulnerable populations and renters without home charging options. As of March 2025, California had installed about 178,549 public and shared- private chargers, including roughly 17,000 DC fast chargers. The California Energy Commission projects a need for about 1.01 million chargers by 2030 to support 7.5 million zero-emission vehicles.

The COVID-19 pandemic accelerated hybrid and remote work and online shopping. These changes caused a sharp decline in activity and transit use in downtowns across California, particularly in transit-oriented downtowns that account for a large share of statewide ridership. This decline has major implications for climate commitments, equity, and the economy. Public officials and business leaders are pursuing a range of strategies to revitalize downtowns and support transit recovery. However, transit ridership has still not returned to pre-pandemic levels.

Heavy-duty transportation modes including trucks, buses, and seaport and airport equipment are relatively hard to decarbonize because of their demanding performance requirements and other factors. The California Scoping Plan for Achieving Carbon Neutrality calls for carbon-neutral transportation across all modes by 2045, with different sectors reaching 100% zero-emission vehicle (ZEV) sales by earlier dates, depending on the type of vehicle (see EO N-79-20). For public transit buses, the state’s Innovative Clean Transit rule requires both large and small transit agencies to cease purchasing combustion engine buses in 2029 in favor of zero-emission (ZE) technologies, with a phased approach that has already commenced. However, for trucks, achieving the transition to ZEVs is more problematic as the state’s Advanced Clean Fleets rule is only applicable to government fleets at present, and the Clean Truck Partnership memorandum of understanding with truck manufacturers is effectively on hold pending legal actions.

California faces the loss of thousands of affordable rental units in the coming decade as affordability restrictions—known as covenants—expire. These agreements, signed between housing developers and government agencies, typically last 15 to 30 years and require that units be rented at below-market rates. When covenants expire, owners can convert units to market-rate housing, often displacing lower-income families.In Southern California alone, over 17,000 affordable units are at risk of conversion, and nearly 70% of these units are located near high-quality transit. If the owners of these properties do not enter into new covenants, these units will be placed on the open market, likely leading to the displacement of lower-income residents to the urban outskirts, resulting in longer commutes and reduced access to reliable transit. To better understand the risk of losing affordable units, we analyzed historic data on affordable housing conversion and identified key factors that influence whether at-risk properties are preserved or lost.

Many suburban and rural communities struggle to provide affordable, efficient public transit. Some have replaced underused fixed-route, fixed-schedule public transit with on-demand, door-to-door microtransit services. In some cases, microtransit has provided better service, though it’s only economical when most trips serve multiple riders. In low-demand areas, limited ride consolidation drives costs sharply upward– often exceeding $50 per rider trip. Transportation Network Companies (TNCs), like Uber and Lyft, could help fill this gap. They already provide door-to-door service with extensive driver networks and low overhead. Yet most public-private pilot programs using TNCs to supplement or replace traditional transit have failed to last beyond their initial funding periods.

Ensuring equitable access to transportation services is critical for supporting the mobility needs of seniors and people with disabilities. In Contra Costa County, California, these populations face significant challenges in finding and using reliable and accessible transit—on demand microtransit services such as paratransit, and other multi-passenger/pooled shuttles or vans—due to the lack of a centralized up-to-date, customer-oriented informational system. These problems are compounded by the difficulties of arranging travel to multiple locations or scheduling trips with different mobility service providers (including paratransit agencies, community-based transit programs, and volunteer drivers programs).

California has ambitious goals to introduce zero-emission technologies across various transportation sectors. Significant progress has been made over the past decades in deploying battery electric light-duty trucks, but heavy-duty diesel trucks are harder to “decarbonize” due to their operational demands and duty cycles, even though the benefits of replacing heavily polluting diesel trucks are significant. Front line communities where diesel vehicles operate the most, especially those near seaports and warehouses, bear the brunt of the pollution from these vehicles and stand to benefit the most from their electrification. Hydrogen fuel cell technology represents a promising approach for transitioning these trucks to zero-emission but the costs and benefits over time must be carefully considered.

California state agencies, public transit agencies, and cities have invested in dozens of microtransit pilot programs, often with the stated goals of improving access, filling gaps in fixed-route public transit service, and serving communities that are difficult to reach by traditional bus or rail. As microtransit services mature, agencies increasingly face decisions about whether to expand, modify, or discontinue microtransit services—and how to allocate scarce operating funds across competing transit priorities.Despite growing investment, there is no consistent approach to measuring whether microtransit services are delivering meaningful benefits relative to their costs, or whether those benefits are equitably distributed. Without clear and well-balanced performance metrics, agencies risk drawing the wrong conclusions about success or failure.