The Boston Globe’s Tim Logan writes about  a study  by the Metropolitan Area Planning Council, which surveyed nearly 200 apartment buildings inside Route 128 and found that about 30 percent of their parking spaces go unused, even in the wee hours of the morning, when most residents are likely home.

Building parking garages is expensive, and unused space devoted to cars can’t easily be repurposed for parks, plazas or larger housing units. Yet officials in many cities and towns, pressured by residents worried about losing on-street parking to newcomers, require new buildings to include a parking space for every unit, and sometimes more.

……The researchers found empty spaces just about everywhere, with the average building’s parking lot about 30 percent vacant. Buildings with easy MBTA access to job centers, or with more affordable housing, tended to have more empty spaces. Buildings in higher-income neighborhoods, and — perhaps ironically — those that provided more parking per unit, tended to have fewer.