Working Paper: NBER ID: w30877
Authors: Lucas J. Conwell; Fabian Eckert; Ahmed Mushfiq Mobarak
Abstract: We propose a theory-inspired measure of the accessibility of a city's center: the size of the surrounding area from which it can be reached within a specific time. Using publicly available optimal-routing software, we compute these "accessibility zones" for the 109 largest US and European cities, separately for cars and public transit commutes. Compared with European cities, US cities are half as accessible via public transit and twice as accessible via cars. Car accessibility zones are always larger than public transit zones, making US cities more accessible overall. However, US cities' car orientation comes at the cost of less green space, more congestion, and worse health and pollution externalities.
Keywords: Accessibility; Public Transit; Urban Economics; Transportation Policy
JEL Codes: Q5; R4
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Larger accessibility zones (R12) | Higher overall city productivity (O49) |
| Larger accessibility zones (R12) | Higher number of commuters accessing CBD (L91) |
| Larger car accessibility zones (R48) | Increased congestion and pollution (L91) |
| Increasing public transit accessibility zones (R48) | Minimal effects on city productivity (F69) |