SAN FRANCISCO -- After decades of scant development, a barrage of new housing units are slated to be built in San Francisco at a furious pace, according to a report released earlier this month.

But the question of how to keep the city's new residents from causing widespread gridlock looms large.

According to San Francisco's most recent quarterly Pipeline Report, some 710 development projects are being considered, potentially offering up a staggering 43,600 new units of housing. Though it's unlikely a large portion of those units will ever break ground, Gabriel Metcalf, the executive director of the San Francisco Planning and Urban Research Association, told The Huffington Post that "we are in the middle of a building boom."

For the past two decades, San Francisco has only averaged 1,500 to 2,000 new units of housing per year. Last year, only a paltry 269 new units went onto the market. Now, as the city's economy begins to strengthen, a much larger percentage of those units are making it through the pipeline.

In the single most expensive housing market in the country (one largely defined by high demand and low supply), the construction of all this new housing is a welcome relief for home-hunters facing staggering price tags and comically long lines at open houses.

These developments aren't without a cost, however. As San Francisco continues to view itself as transit-first, experts worry the inevitable influx of individuals will put increased strain on the city's public transportation system.

San Francisco Municipal Transportation Agency spokesman Paul Rose told HuffPost that the city is already taking a number of proactive measures to handle its new citizens. "Within the current decade, we will see a large expansion of Muni service," he said, pointing to the Van Ness Bus Rapid Transit expected to debut in 2018, as well at the Geary Street Bus Rapid Transit and controversial Central Subway project scheduled for the following year.

But the expansion won't come cheap, and as Muni adds routes and introduces new vehicles into its fleet, the gap between what it costs to run the system and the money it brings in from ticket sales will continue to grow.

"Throughout the transit industry, routes aren't usually profitable," Rose insisted. "We don't expand service in order to make more money; we do it to meet a need."

An agency running an annual $70 million structural deficit and a $420 million backlog in deferred maintenance, Muni already has difficulty serving the San Francisco's current population. "We've been so negligent as a city in terms of our lack of investment in Muni that the system doesn't have the capacity to meet our existing needs," Supervisor Scott Wiener told HuffPost. "The solution isn't to stop adding housing, the solution is to be much more serious about making Muni work."

For Muni to keep its current fleet in a state of good repair, SFMTA managers estimate they would need an extra $260 million per year.

Wiener recently requested that Muni begin issuing monthly reports to the Board of Supervisors detailing the state of its system. By crystallizing this data on a month-to-month basis, he hopes to see renewed political support for increasing Muni's funding.

Wiener also noted that Muni needs to reform itself internally, touting that the agency had made significant progress toward implementing solid changes in recent years. He agrees that expanding the overall size of Muni's funding pie is essential to meeting San Francisco's growing needs.

One such suggestion the lawmaker recently proposed? Increasing the city's vehicle license fee for car-owners, creating funds which would ideally go directly into Muni's coffers. Wiener hopes to place a ballot measure approving the hike before voters in 2014.

"I think, in short, the current system would not be able to handle a big influx of new riders without some major improvements," said Transit Riders Union Spokesman Ben Kaufman, who noted that San Francisco has the slowest mass transit system of any major city in the nation.

"Bus Rapid Transit along Geary Street has been talked about since at least 1990, but that likely won't be on the ground for years," he added. "You could say the deliberative process in San Francisco goes on for a while."

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