Long-Term Changes in Accessibility

Access Across America Transit Methodology 2014 — The annual Access Across America reports produced by the Accessibility Observatory began in 2014.

If short-term changes in accessibility can be usefully decomposed to examine relative influences of land use and transportation network change, the long-term accessibility trends represent the combined evolution of these two forces over many years. The direct and indirect influences of DOTs on mobility and land use are captured over time through the accessibility in each place. Long-term trends in job accessibility in urban areas will synthesize economic conditions (growth or shrinkage of job opportunities), as well as the transportation conditions (infrastructure investments and congestion).

The NAE has used consistent methodology to describe accessibility in each residential block of the US since 2017. The resulting values can be explored using time series of average access, experienced by the typical resident of each of the top 50 most populous urban areas in the US. Importantly, the years in which daily travel was most disrupted by the COVID-19 pandemic (2020-2022) are included in the timeseries, allowing the access performance measure to reveal how the dynamics of infrastructure, land use, and travel behavior have responded in the COVID era.