Shrinking cities, also known as legacy cities, are previously dense urban areas that have experienced significant population loss. Some of the most striking examples in the United States are historical automobile manufacturing cities like Detroit, Buffalo and Cleveland.

In these cities, the thinning of the population coupled with the decay of physical infrastructure creates unique transportation challenges.

University of Utah researcher Joanna Ganning set out to find a tailored solution for this problem using accessibility-based transportation planning.

She will present her research in a webinar on Thursday, February 19.

In contrast to mobility-based planning, which focuses on the cost of transportation per mile traveled, accessibility-based planning places its emphasis on whether people have access to their destinations.

Ganning believes that there is a heightened need for accessibility-based planning in urban settings with population decline.

“We know that increased population density makes transit more efficient. In urban decline you’re losing people, so you don’t have that working for you,” Ganning said.

The challenge of running a transit system that was designed to serve a much larger population than it currently sustains can result in service problems. This problem may be amplified in lower-income neighborhoods and among underrepresented populations, who often lack the political clout to rally support and who have less common access to personal vehicles.

“Just as distinct as the need for access is, the challenges to accomplishing it are also distinct – and rather severe,” Ganning said. “In shrinking cities, and particularly among minority populations that have been victimized by urban renewal and other public policies that have not served them well, there is a level of mistrust in the policy process itself that must be overcome.”

Shrinking cities have higher unemployment rates, lower incomes, and more people requiring public assistance or food stamps when compared with the United States as a whole.

As commuting by car is often a money-driven choice, it frequently happens that people with greater economic need lack the option of commuting by private vehicle, so that the greater time they spend commuting on public transit reduces the hours they are available to work. Addressing these broader quality of life issues is a necessary part of attaining transportation accessibility.

Improving walkability, for example, is an indirect yet demonstrable way for planners to improve access to transit. In shrinking cities, this can be accomplished by securing, cleaning up, and policing vacant lands and buildings as well as through traditional measures like sidewalk upgrades and crosswalk improvements.

If accessibility planning is to be a solution for shrinking cities, it will have to be specifically tooled to the contexts of those cities and the inherent challenges they contain. Ganning's research offers a framework for approaching that task.

For more information, visit the project page or download the report.