Mass transit may be good for the environment and traffic relief, but every single Golden Gate Bridge district bus ride between the North Bay and San Francisco requires a nearly $20 public subsidy.

And the bridge district’s buses aren’t the only ones running on the public dime. In fact, $1.85 billion in toll and taxpayer dollars were spent to keep the region’s top bus, rail and ferry systems operating last year, according to number crunchers at the Metropolitan Transportation Commission.

“The Bay Area voter has certainly been generous over many years and has passed tax measures to fund public transit,” said MTC spokesman Randy Rentschler.

The highest subsidy per ride is the Golden Gate Bridge, Highway and Transportation District’s bus service, in which passengers pay $5.20 for a ride from Sausalito to downtown San Francisco that actually costs the district $24.68.

To keep the buses running, the district pumps $59 million a year in sales taxes and bridge tolls into the operation. That’s an annual subsidy of $5,632 for each of the transit agency’s 10,491 weekday riders.

On the Peninsula, SamTrans bus service gets a $12.85-per-ride subsidy, which works out to $2,536 a year for every weekday rider.

Riders on the Santa Clara Valley Transportation Authority’s light-rail system pay less than $1 for what is really a $12.26 ride.

Other subsidies range from the Contra Costa County Connection, at $7.26 a ride, to AC Transit, at $6.87 per ride. San Francisco’s Muni’s tax subsidy works out to $2.86 per ride.

BART, Caltrain and bay ferries get subsides as well, but riders still pay most of the costs.

For example, Golden Gate Ferry riders pay, on average, $8.82 for what is really a $13.07 ride across the Bay.

BART riders pay $4.26 for a $5.55 ride from suburban Lafayette to Powell Street in downtown San Francisco.

In general, dense urban mass transit where ridership is higher is much more cost-efficient than in the suburbs, where buses often roll near empty outside the morning and evening commute hours.

“It’s plain and simple,” Rentschler said. “The Bay Area’s postwar suburbs were built for cars — not public transit.”

One factor contributing to the high cost of light rail in the South Bay is the cost of maintaining the tracks and trains, Valley Transportation Authority spokeswoma Brandi Childress said.

Childress said VTA has one of the highest pay structures for bus and light-rail operators in the Bay Area.

“Our operators are the third-highest paid out of 234 agencies in the country,” she said. “Mechanics are the second-highest paid out of 207 agencies.”

There is some good news in all this.

Golden Gate district spokeswoman Priya Clemens estimated the subsidized bus and ferry service cut down vehicle traffic on the Golden Gate Bridge by 20 percent during rush hour.

“That’s a big intentional benefit to commuters,” Clemens said.

Cashing in: Gavin Newsom’s election as governor has set off a gold rush among his political friends, allies and advisers in the lobbying world.

Lighthouse Public Affairs of San Francisco is already beefing up its Sacramento lobbying office. One of Lighthouse’s founding partners is Rich Peterson, a longtime Newsom supporter who chaired the finance committee for both of Newsom’s mayoral campaigns.

Word is Jason Kinney, a longtime member of Newsom’s inner circle and a Sacramento lobbyist at the the prominent California Strategies firm — founded by Gov. Pete Wilson’s chief of staff, Bob White — will soon strike out on his own.

“Nothing has been decided,” Kinney said, adding he plans to do “whatever I can to be helpful” to Newsom. “And I don’t know what it is going to require at this point.”

Former Newsom mayoral press secretary Nathan Ballard, who operates a public relations firm in San Francisco, said he expects “to have an expanded footprint in Sacramento,” as well.

“Everyone is smart to get in there if you have some connection,” Ballard said.

Tony Winnicker, another former Newsom press secretary and adviser to tech titan Ron Conway, could also land in the mix of conduits to the new governor.

Meanwhile, SCN Strategies, the political consulting firm that ran Newsom’s races for both governor and lieutenant governor — as well as the races of Gov. Jerry Brown and U.S. Sen. Kamala Harris — is about to undergo some big changes. Partners Ace Smith and Sean Clegg are becoming increasingly busy as Harris ascends the national stage for a possible presidential run. Meanwhile, partner Dan Newman plans to go his own way, though we’re told he will partner have some role in Newsom’s political orbit.

But Chris Gruwell, a longtime San Francisco lobbyist formerly affiliated with Darius Anderson’s Platinum Partners, urged caution to anyone thinking he or she can waltz into Sacramento and start selling access to the new governor.

“Any friends who think they can sell influence over Gavin don’t know him very well,” he said.

San Francisco Chronicle columnists Phillip Matier and Andrew Ross appear Sundays, Mondays and Wednesdays. Matier can be seen on the KPIX-TV morning and evening news. He can also be heard on KCBS radio Monday through Friday at 7:50 a.m. and 5:50 p.m. Got a tip? Call 415-777-8815, or email matierandross@sfchronicle.com. Twitter: @matierandross