Justified or not, complaining about Muni is a time-honored San Francisco pastime. Commentary — whether on social media, in a bar or on Muni itself — generally focuses on three major themes: arrival times, speed and odor.

The perpetual grousing shouldn’t be much of a surprise, however, considering the unavoidable problems that come with an ostensibly underfunded system carrying 700,000 daily riders through one of the densest urban landscapes in the U.S.

Though some routes might seem slow and crowded even now, Muni appears to be in for a steep spike in users. Based on a new regional projections report, The City will grow by 35 percent — around 280,000 more people — between 2010 and 2040, a period of buildup unseen since the 1950s. In less than 20 years, 1 million people will live inside San Francisco’s borders, according to upcoming numbers from the Association of Bay Area Governments.

If Muni’s ridership increases in proportion with the current 825,000 population, that could mean more than 200,000 additional people on buses and Metro light-rail cars — every day.

The potential surge is not lost on the San Francisco Municipal Transportation Agency or Mayor Ed Lee. The mayor is in the beginning stages of pitching an increase in vehicle license fees and wants general obligation bonds on future ballots to fill a projected $6.3 billion funding gap that he says is needed to maintain the current system.

If approved, the money is slated for street fixes and hundreds of new transit vehicles by 2040. A transportation task force recently formed by the mayor recommends 260 new light-rail vehicles — 151 to replace aging cars, 24 new cars for the Muni Metro’s Central Subway extension and 85 more to accommodate additional ridership. The task force also recommended that the current fleet of 810 buses be enlarged by 118, including several larger models to replace smaller versions.

If the funding doesn’t come through, SFMTA officials fear more “rider discomfort” and increased “bunching” of slower buses that notoriously clog the streets during rush hour.

“Without a new investment, transit crowding is projected to get worse in the future, expanding to more routes at the busiest times of the day,” said Paul Rose, a spokesman for the SFMTA. “Gridlock and traffic would discourage new jobs from locating in The City.”

Rose said the agency is striving for a 50-50 “mode shift” wherein half of commuters are taking transit, walking, bicycling or using taxis, and the other half travel by personal vehicle. Currently, 60 percent of commuters in The City use their own cars, according to SFMTA estimates.

Gabriel Metcalf, executive director of the think tank SPUR and a member of a recent special committee to identify Muni’s funding issues, said no such shift to transit will happen without significant improvements to the system, including widening the gaps between bus stops to improve Muni’s dismal 8 mph average travel time.

“If we don’t make a major reinvestment, we’re going to see more breakdowns, more vehicles going out of service, and ultimately we’ll see a vicious cycle of declining ridership,” Metcalf said. “We’re still one of only a small number of American cities where our transit service is for everyone; the problem is that it’s too slow. I think this is the single most important thing we could do to improve livability.”

Considering The City’s other rising expenses, SFMTA Transportation Director Ed Reiskin said that for some people public transit is the major difference between being able to live in San Francisco or not.

“What makes the quality of life here so great has to do with the ease of how people can get around,” Reiskin said. “It’s one of the things that offsets the higher cost of housing.”

Supervisor Scott Wiener, who also works on regional transit issues with the Bay Area’s Metropolitan Transportation Commission, said municipal infrastructure updates often fall low on a list of priorities because the failure to keep pace with long-term deterioration almost never presents short-term political consequences.

Still, he said, the projected population increase presents a “crisis” for Muni and the Bay Area transportation system in general.

“Muni is not meeting the needs of current San Francisco residents, much less the 200,000 people who are yet to come,” Wiener said.

San Francisco at 1 million

The City is poised to hit the mark in less than two decades. This five-part series will explore the challenges San Francisco faces in handling this population milestone.

SUNDAY: What will San Francisco look like with 1 million residents?

MONDAY: Utility operators prepare for the population crush

TUESDAY: More people means more work for police and fire personnel

THURSDAY: Muni will need big changes to handle big boost in passengers

FRIDAY: Housing philosophy of “build more now” sure to be tested in the futureBay Area NewsSan FranciscoSan Francisco at 1 millionSan Francisco public transit

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