Use of multimodal accessibility metrics in project prioritization and investment

By Saumya Jain
The Accessibility Observatory at the University of Minnesota recently released a one-of-a-kind report that ranks the country’s 50 largest metropolitan areas (by population) according to accessibility to jobs via bicycle. The report is a product of a multi-year study, where the researchers analyzed land use and transportation systems to measure accessibility to destinations via different modes. The researchers also incorporated traffic stress and bicycle comfort in measuring accessibility.
Using census tract-level accessibility analyses, the study developed two stress-level metrics: jobs that can be reached by low-stress routes and jobs that can be reached by medium-stress routes. The study defines low-stress routes as separated bike lanes and paths, and medium-stress routes as all streets with bike infrastructure, unprotected bike lanes, shared lanes, and some non-arterial streets. The report shows that many cities have very different bike-accessibility scores, depending on whether the low-stress or medium-stress networks are used. To quantify the scope of improvement for moving towards low-stress accessibility, the researchers also developed a third metric, maximum-possible bike access. The difference between medium-stress access and maximum-possible bike access is intended to help policymakers and city staff make better investment decisions and prioritize those projects that will have the greatest impact on bike access to jobs.
Hawaii and Virginia DOTs, with continued support from SSTI, have also been using accessibility metrics in multimodal project selection and prioritization. Our multimodal accessibility metrics are quite similar to those used by the Accessibility Observatory, with one small difference: Instead of having different metrics based on traffic stress levels, we incorporate level of traffic stress as a travel-time impedance.
This report is an excellent data source for cities and metropolitan areas that wish to identify gaps in their bicycle networks and improve job access by making cost-efficient investments. We hope to see policymakers and cities make use of this publicly-available resource and look forward to future publications related to the ongoing study.
Saumya Jain is a Senior Associate at SSTI.