Overabundant parking fuels car-oriented living in greater Boston

By Chris McCahill

A new report from the Metropolitan Area Planning Council reveals 30 percent of residential parking in the Boston area goes unused at night. This new study builds on an earlier report, featured in an SSTI webinar, growing the sample from 80 properties to 189 across 14 municipalities throughout the city’s inner core. The additional data also let MAPC test for significant factors affecting parking demand.

Figure 1. Depiction of typical residential parking use. Source: MAPC

Sites with good transit connectivity and more affordable housing generally had lower parking demand, but the single most important factor was parking supply. In other words, according to the report, “the availability of parking is attracting car-owning households and influencing their behavior,” even in transit-rich areas. Nonetheless, the average apartment or condo uses less than one parking space per unit.

These findings are generally consistent in cities across the U.S. Residential parking is only 69 percent occupied in Seattle, 60 percent occupied in DC, 56 percent occupied in Chicago, and 67 percent occupied in Madison, WI, where SSTI conducted its own study. MAPC estimates that the 5,910 empty spaces in their study represent $94.5 million in development costs, or roughly $5,000 per housing unit.

Based on its findings, MAPC recommends several steps for municipalities: 1) require less parking in their zoning codes or eliminate requirements altogether, 2) design transit-oriented development with transit-oriented households in mind, 3) “unbundle” parking costs so people don’t pay for parking they don’t need, and 4) build more affordable housing with less parking.

The full report and data from the study are available for download at MAPC’s Perfect Fit Parking website, along with an interactive map.

Chris McCahill is the Deputy Director at SSTI.