We evaluated transportation system performance in the Portland metropolitan area, using an indicator on multi-modal accessibility via transit, biking, and walking. We find that the rail system in Portland metropolitan area has a great impact on transit accessibility for short-duration trips, especially within Portland city limit. Light rail stations provide exceptional accessibility to immediate locations. With only bus routes, accessibility metric is at a low level homogeneously within core Portland. Our analysis can inform planning decisions on emergencies such as NYC subway system during hurricane Sandy and London Tube strikes.

15-minute isochrones by transit, biking, and walking from a location at Portland, Oregon at 8 am weekdays.

Census block-level choropleth map of access to residential population in 30 min by bike-transit, departing during 7am-9am on a weekday.

Accessibility map under the no-rail-transit scenario, all else being equal.

Ruda Zhang
Postdoctoral Fellow