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In transit-rich Arlington, parking spots in residential high-rises remain empty, even at times of “maximum capacity,” according to a new study by Arlington County Commuter Services’ Mobility Lab researchers, who will distribute their data to engineers who produce a nationwide manual on development.
Researchers surveyed residents living in 16 high-rise towers, most within a mile of a Metro station, to gauge their commuting habits. Among the study’s key findings is the number of car trips made by residents decreased as mixed-use density increased. Residents, even in condos where car ownership was more prevalent, left their cars at home and chose public transit, walking, or bicycling.
“Even during the day when you’d expect cars to be out of the garage, forty percent of the spaces were still occupied, so people were taking other modes to get to work,” said Mobility Lab’s Howard Jennings. At maximum capacity, roughly one-fifth of the spaces were still empty. “So it does suggest that many of these garages were built a little larger than the demand for them.”
Jennings' research is designed to help the Institute for Transportation Engineers update its manual that has been used by planners for decades to determine how much parking is necessary. The question of how to “right-size” parking is vexing: residents’ habits, demographics, and development patterns are changing.
“We want to right-size the parking, certainly. We want there to be enough without their being an excess. That is one of the policies in [the county’s] master transportation plan,” Jennings said. “So getting the parking right is a part of that, and parking does play a role in how many vehicles trips are generated.”
Excess parking is an enormous waste of money and real estate. Building underground parking garages, for example, can cost tens of thousands of dollars per space, driving up rents. But one expert says Arlington already has enough parking; it simply needs to be managed better, a lesson for an entire region grappling with congestion as residential, retail, and office development accelerates.
“If they put in management right now, it is probable that they would stop building parking decks for about a decade,” said Chris Leinberger, a real estate and land use expert at George Washington University. Leinberger is the president of LOCUS, a national network of real estate developers.
“We are still learning how to right-size parking,” said Leinberger, who said mandatory parking minimums imposed on developers should be abolished in favor of allowing the marketplace to drive decisions. He faulted banks and investors for pushing for too much parking in the nation’s urban areas, as well as neighborhood groups who are worried traffic will spill onto their streets if motorists are unable to find spaces.
In the study area examined by the Mobility Lab researchers, the parking minimum was 1.12 spaces per residential unit. Most of the 16 high-rises built close to that ratio, the highest being 1.55. Leinberger said Arlington could get by with a minimum of .9 spaces per residential unit in its walkable downtown areas.
A system to manage existing parking assets is the best solution to excess spaces, Leinberger said.
“What these walkable urban places need—like Clarendon, like Rosslyn – is common management of all their parking, whether it is publicly-owned or privately-owned,” Leinberger said.
“It would not surprise me if on average parking spaces in Arlington’s walkable urban places are on average 50-55 percent utilized on a 24/7 basis. They have plenty of capacity for the next decade of development if they managed what they had in a more efficient manner. Office space uses its parking between 8 a.m. and 6 p.m. five days a week. Restaurants need those parking spaces at night and on weekends.
Residential needs those parking spaces at night. Walking a couple blocks from your assigned space to get home is not a big deal.”
“The biggest development trend of the next generation will be the urbanization of the suburbs. The most urbanized suburb in the country is Arlington,” Leinberger added.