Which Communities Suffer the Most from Neighborhood Severance Caused by Freeways?

Research Lead: Adam Millard-Ball

UC Campus(es): UCLA

Problem Statement: The racial legacy of freeways has come into stark focus in the past year. A recent Los Angeles Times article calls the region’s freeway system “one of the most noxious monuments to racism and segregation in the country.” A key feature of past freeways construction has been neighborhood severance. Freeways disrupt the neighborhood street grid, creating particular hardships for pedestrians who must take circuitous routes to access transit and to walk to stores, schools, and other destinations. The impacts of disconnected streets on walking and public health are well documented, but the environmental justice dimension of connectivity has remained unexplored, as has the link between street connectivity and local planning efforts. Reducing neighborhood severance is also a key goal in Caltrans’ 2017 bicycle and pedestrian plan, Towards an Active California. The plan commits the agency to identify and improve highway crossings and to prioritize improvements based on equity criteria.

Project Description: The research team will test whether Black, Indigenous, People of Color (BIPOC) communities suffer greater neighborhood severance effects based on four measures of connectivity: local street connectivity, connectivity for transit access, the number of freeway crossings per mile, and the quality of those crossings (e.g., pedestrian comfort). The first two measures are based on street characteristics such as circuity and the proportion of streets that are dead-ends. The project team will also examine the strength of the relationship between these four connectivity measures and the race/ethnic composition of the neighborhoods, based on 2020 Census block-level demographic data, and on the age of the constructed freeways, to determine whether planners have become more attuned to severance effects over time. Finally, the researchers will consider where new or upgraded crossings would yield the greatest connectivity benefits, particularly in BIPOC communities, by simulating the addition of new crossings and the removal of existing crossings, to determine which improvements have the greatest potential to reconnect street networks and improve pedestrian and bicycle access to transit.

Status: In Progress

Budget: $71,230

Project Partner(s): Los Angeles County Metropolitan Transportation Authority