Hard to believe, but San Francisco’s transit wonks were caught completely off guard by the ride-hailing revolution that now floods the city with thousands of cars daily.

In fact, when the city was drawing up its transportation “Major Strategic Plan” back in 2012, planners thought “ride shares” meant car pooling. So as the Municipal Transportation Agency drew up a blueprint for more bus- and bike-only lanes — and less space for cars — it was blind to the wave of Uber and Lyft cars that was about to inundate the streets.

“I don’t think anyone anticipated this would happen, including Lyft and Uber,” said transportation agency chief Ed Reiskin.

Randy Rentschler of the Metropolitan Transportation Commission, which oversees regional transportation planning, said city officials may have fallen victim to their vision of how things should be instead of how they are.

“Public policy often aims for a certain outcome — and as such, it can be harder to predict what you don’t want to happen, so you don’t see it,” Rentschler said.

In fact, Uber and Lyft now carry 283,000 people per workday in San Francisco and make up 9 percent of all vehicle trips in the city, according to a recent survey by the city Transportation Authority.

And for the first time in years, Muni ridership has dropped.

City Hall is increasingly interested in ways to ease the congestion that some officials blame on ride hailing. City Attorney Dennis Herrera has subpoenaed documents from Uber and Lyft to try to determine whether the firms are complying with city traffic, disability access and environmental regulations. Supervisor Jane Kim has suggested a 20-cent-per-ride fee to raise money for unspecified anticongestion measures.

Uber has put out feelers that it would be willing to talk with the city. But it wants the conversation to include all aspects of congestion, including the surge in double-parked delivery trucks, the growth of bike lanes and other street reconfigurations designed to slow traffic.

“The feeling (at City Hall) seems to be, ‘If you can’t beat ’em, tax ’em,’ but at this point I’d just like them to give us more information so we can see what is really going on,” said Supervisor Aaron Peskin.

Wouldn’t we all.

On your marks: Michael Cardoza, a high-powered defense attorney and former prosecutor who has gained attention over the years as a TV legal analyst, is weighing a possible run to succeed disgraced former Contra Costa County District Attorney Mark Peterson.

“I am giving it serious thought,” Cardoza told us the other day after he was spotted at the Walnut Creek Yacht Club restaurant with a potential supporter.

“I know this (D.A.’s office) needs leadership, and I don’t believe it should come from inside,” Cardoza said. “They are too in bed with the people there and don’t see all the real problems.”

Two prosecutors have already announced their candidacies for Peterson’s old job — Deputy District Attorney Paul Graves and former Deputy District Attorney Patrick Vanier, who is now a prosecutor in Santa Clara County.

Peterson resigned June 14 after cutting a plea deal with state prosecutors who had charged him with 13 felonies connected to his use of $66,000 in campaign donations to pay for such personal items as meals, gas, clothes, movie tickets, hotels and phone bills.

The plea deal allowed Peterson to plead no contest to a single count of perjury for making false statements on state campaign disclosure forms.

Doug McMaster, chief assistant district attorney, is handling the office’s day-to-day operation while the county Board of Supervisors takes applications for Peterson’s replacement. Its goal is to pick a replacement by mid-September.

“That person can choose to run along with other candidates” for a four-year term in the June 2018 primary, said Supervisor Karen Mitchoff.

McMaster has made it clear that he is not running and will not seeking the appointment. Graves and Vanier haven’t disclosed whether they are applying to the supervisors. They have until July 23 to decide.

Whoever gets the job will have some work to do in bringing calm to the district attorney’s office. The Peterson scandal came close on the heels of another case that had divided the department for years, in which a deputy district attorney was accused of raping a junior colleague in 2008. The criminal case against the deputy was eventually dropped, and he returned to work two years ago.

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