Trends in Transit Access

Influencing land use through transportation investment is not only a freeway mechanism. Going back to the electric streetcar era, public transit systems in the U.S. have been used as tools to change land use patterns. The concept of transit-oriented development (TOD) as practiced reflects the idea that the high-quality, frequent transit line comes first, increasing accessibility to destinations from station locations, followed by development which aims to take advantage of that increased access.

Transit accessibility is influenced by the coordination of land use and travel networks, as is auto accessibility. However, access via transit is structurally constrained differently than auto accessibility. Transit access is defined by slower vehicle travel times, the walk or roll times to get to and from stops and stations, and especially the need to coordinate trip departures with vehicle schedules. The wait between desired departure time and transit vehicle departure (or the wait between necessary arrival and desired arrival at the destination), reduces the number of opportunities reachable in a given amount of time. The influence on reducing wait time to increase access has led to the slogan “frequency is freedom” when considering changes to schedules. Regardless, transit job accessibility is often more spatially constrained and variable than auto access (Figure 3.3, compare to Figure 3.1).

The time series of transit accessibility across the US looks different than the auto mode, because of the difference in how transit accessibility feedbacks work. Rather than being constrained by increased demand, as is auto accessibility through congestion, transit accessibility is almost entirely determined by the level of service provided by an agency. Increased use in the form of ridership does not feedback to limit accessibility except in edge cases of near-full capacity. Instead, more riders can provide a diffuse positive feedback on transit accessibility by increasing the revenue available for providing service. As explored in Transit Accessibility Changes, the differences in travel times from place to place, and the coordination of destinations with transit service, can produce large variability in accessibility. This is true within urban areas, but also over time as well.

Prior to COVID-19, this variability is evident in the timeseries (Figure 3.4), as individual lines representing urban area averages change from year to year. The arrival of the pandemic outbreak in 2020 had a similar impact on transit ridership as on congestion, in the form of 50% or more reductions in transit ridership. Unlike with auto congestion, the drop in ridership did not feed back to cause drastic changes in accessibility. In 2021, some places experienced overall increases, some small decreases, as transit agencies used federal funds to replace their disappearing fare revenue, and kept services fairly constant. By 2022 and 2023, however, the broader social travel behavior changes led agencies to begin to reduce offerings, especially to downtown office commuters, but also reducing service in general. 

Residents in the majority of the top 50 urban areas experienced lower average job accessibility than they had in 2019. In some of the largest transit systems, the declines were the biggest. In the San Francisco Bay area, the typical resident could reach 20% fewer jobs in 2023 than in 2019. In Chicago, the decline from 2019 was 22%; even more dramatically, the average jobs reachable in 30 minutes in the Chicago region had actually increased in 2021 as commuter services stayed running, but by 2023 access was down 34% from that COVID-era peak.

Some urban areas did see modest increases from 2019 to 2023, among them Milwaukee, where residents could reach 5% more jobs on average. Phoenix held fairly steady, with only about a loss of a thousand jobs reachable in 30 minutes. Still, because of the poor accessibility in the region even before COVID, this represented a 10% decrease in access for the average resident. In 2023 there were 2.2 million jobs in the Phoenix region, and in 30 minutes using transit the average resident could reach just about 10,000 of them.