SSTI researcher: ‘Parking requirements transform cities, cost millions in tax revenues’

By Chris McCahill

Colleagues from the University of Connecticut and I recently completed a pair of studies examining the long-term, citywide impacts of parking facilities and minimum parking requirements. Our research shows how parking minimums can physically transform urban centers, stifle development, and cost cities millions of dollars in annual tax revenues.

These two new studies build upon several years of research analyzing changes in land use, transportation infrastructure, and travel behavior in small cities around the nation. Early on, this work revealed that parking supplies in some cities had roughly tripled since 1960. We have since explored the causes and implications of these changes.

Parking supplies in downtown Hartford, Conn., in 1957 (left) and 2009 (right); surface lots are shown in red and parking garages are shown in brown.

Parking supplies in downtown Hartford, Conn., in 1957 (left) and 2009 (right); surface lots are shown in red and parking garages are shown in brown.

Our analysis, described in UConn Today, found that land used for parking often generates far less tax revenue than land used for buildings—anywhere from 58 to 93 percent less in the cities we looked at. The difference in taxes may discourage developers from converting surface lots into more productive uses. It also costs some cities more than $1,000 per space in annual tax revenues. Since employees use much of that parking, this is effectively a subsidy for those who drive into each city for work, paid for ultimately by residents.

A great deal of prior research supports the notion that, over the long run, excess parking can fragment cities and make them less attractive to potential residents, businesses, and developers. Among the six cities we looked at, those that grew the most during the past several decades actually experienced decreases in parking supplies, which suggests to us that zoning codes that require off-street parking are at odds with development goals in urban areas. City officials can help align policies and programs with those goals by reducing or eliminating parking minimums and even imposing parking caps; by restructuring tax codes to encourage development on surface parking lots; and by investing in programs that improve the range of local travel options.

The two papers—co-authored by UConn professors Norman Garrick and Carol Atkinson-Palombo and me, along with students Bryan Blanc, Michael Gangi, and Jessica Haerter-Ratchford—were presented at the Transportation Research Board’s annual meeting in January. Both will be published in upcoming issues of the Transportation Research Record journal. Papers presented at the annual meeting are available from TRB’s online compendium.

Chris McCahill is a Senior Associate at SSTI.