Can parking lot capacity limit transit station capacity?

By Robbie Webber

Greater Greater Washington recently outlined the cascade of implications of having poor pedestrian and bicycle connections to some DC-area transit stations in suburban locations. One of the problems they mention is that if walking or bicycling to a station is unappealing or dangerous, everyone will drive and the capacity of the parking lot effectively limits the capacity of the transit station. Once the parking lot is full in the morning, no one else can use the station because it is difficult to walk or bike, and connecting bus routes offer poor connections as well. As the author points out, this may account for the fact that these stations have some of the lowest ridership in the system.

WMATA conducted an analysis of the origins of riders parking at their lots next to Metro stations and found that some (mostly those at the end of the line) draw customers from far away, while others are patronized mostly by riders from within five miles. A few stations draw a large portion of their parking patrons from within three miles, a distance that is easily traversed by bicycle or foot. One station draws two thirds of its parkers from within two miles, while another draws 30 percent of its parkers from within one mile of the station.

So why are people driving from such short distances? There are a number of reasons why people do not walk or bike to the stations. Street connections restrict access to some stations. Rail yards and vacant lots surround others, and accessing several lots requires a crossing of the Capital Beltway to reach the majority of housing close by. As the blog post points out, this is surely an opportunity for transit-oriented development. But even more important, it highlights the need for pedestrian and bicycle planning to and from transit stops. Parking lot capacity should not limit the capacity of the station.

Robbie Webber is a Senior Associate at SSTI.