Gillen warns that the increased mandatory parking minimums supported by Clarke and Blackwell could have unintended consequences. Forcing developers to build more parking spaces when they build housing could put the brakes on new units, especially those that are more affordable for middle-to-working class people. Some projects simply won’t get built, while others will focus more on larger, luxury buildings so they can make up the additional cost by selling fewer units of higher priced housing.

Gillen noted that Oakland, Ca. enacted a similar parking mandate in the 1960s. A study showed that mandate increased construction costs, which were passed onto residents in the form of pricier housing. Parking mandates there pushed developers to build more high-end residences, and less affordable housing. “At the time of the change in its zoning law, Oakland was a predominantly blue-collar city with a housing stock disproportionately composed of modest attached rowhomes of workforce housing,” Gillen writes. “In other words, it was very similar to the Philadelphia neighborhoods that [Clarke’s] bill is intending to help.”

But Gillen said that he doesn’t envy City Council’s position. He doesn’t believe there are any easy options here and that all of them have serious downsides, be they political or economic.

“The logical response is that if people are placing an actual dollar value on something, but they are getting it for free, then you should charge them for it,” said Gillen. “We should be charging in the neighborhoods where demand exceeds supply of free on-street parking. How politically possible or palatable is that? I imagine it would meet with enormous resistance.”

Another option would be transitioning to less car-centric lifestyles, where residents in these neighborhoods own fewer cars per household and more frequently use transit, bikes, car share services, and their own two legs to get around. But Gillen said the possibility of such a lifestyle change is highly variable depending on which older neighborhood you live in. It is relatively easy to get to jobs and amenities without a car in South Philadelphia or University City compared to Mayfair or Olney.

Then there is the option which presumably most Philadelphians, elected or otherwise, would like to avoid: If neighborhoods lose population, the problem will solve itself.

“We could return to a city that is declining and depopulating,” said Gillen. “You know what city has tons of free on street parking? Detroit.”