The city’s proposed congestion toll should first target the “real” cause of gridlock — Uber and Lyft, according to a study by a former Big Apple transportation commissioner.

The app-based for-hire vehicles account for 43.9% of Midtown Manhattan traffic, or more than either cabs or personal vehicles, according to research by Lucius Riccio, a Stern Business School adjunct professor who served as DOT boss under Mayor David Dinkins in the 1990s.

Based on that, the city should focus its congestion-pricing toll plan on app-based  services at least at the outset, Riccio said.

“The largest share of the vehicles on our streets are these for-hire vehicles that pay nothing to be on our streets,” he told The Post on Tuesday.

“There’s nothing wrong with congestion pricing [but] for-hire vehicles should be charged first. People should recognize they’re the real cause of congestion in Midtown.”

In 2019, for-hire hacks began paying a $2.75-per-ride congestion charge which is not part of the toll plan.

But Riccio noted that yellow taxi drivers currently pay around $15,000 in general annual fees. If the city charged app-based cars $5,000 in such fees per year, it could raise half a billion dollars, according to his estimates. A congestion-pricing toll targeting for-hire drivers at the start would only help level that playing field further, he said.

For his study, Ricco based his congestion results on 90 short videos he shot of daytime traffic at several Midtown intersections in October and November, tallying up each vehicle type he observed.

“Although this group may not be a perfect random sample of Midtown, it is a varied collection of locations with a large number of vehicles observed,” he wrote in the study.

Speaking to The Post, Riccio pinned blame for the results on city leaders who permitted Uber, Lyft and other companies to enter the market with almost no barriers to entry.

“The people who are advocates for congestion pricing did not speak up at all when 100,000 for-hire vehicles — Uber, Lyft, etc. — were allowed for almost nothing, no charge, to fill up our streets,” Riccio said.

The MTA’s congestion pricing program was passed by the state legislature and former Gov. Andrew Cuomo in 2019. It is set to go into effect no earlier than the end of the year, with tolls being recommended by a select panel and approved by the MTA board.

The plan aims to reduce overall traffic in Manhattan’s downtown by charging anywhere from $9 to $23 per vehicle entering the borough below 60th Street.

Critics say the move could badly hurt the immigrant-dominated taxi and app-based industry, with the MTA is warning some drivers may be put out of work as a result.

Taxi analyst Bruce Schaller, who helped craft ex-Mayor Michael Bloomberg’s failed congestion pricing proposal in 2007 and 2008, said Riccio is right to point out the disproportionate presence of app-based cars.

But Schaller cautioned against charging them the congestion fee while exempting taxis, even at the start. Doing so would simply push customers to yellow cabs and not cut traffic, he said.

“You’re not exempting cabs or Ubers or Lyfts or whatever the case may be, you’re exempting the people in them, and they’re fungible, they’ll move around,” Schaller explained.

“You would benefit the [yellow taxis], which is a good thing, but you’re not accomplishing your actual goal of reducing congestion,” the analyst said. “It would be a disaster if we put congestion pricing in and we didn’t see a benefit.”

A rep for Uber disputed Riccio’s findings — pointing to a report from August by the city’s Taxi and Limousine Commission that concluded the “return of congestion shortly after the initial onset of the pandemic … cannot be attributed to the FHV industry.”

The Uber spokeswoman, Freddi Goldstein, added, “A recently released review by the TLC found that the return of congestion in Midtown could not be attributed to the for-hire vehicle industry.

“Despite that fact, Uber, Lyft and Taxi riders have already paid nearly $1 billion in congestion fees since 2019, while other vehicles clogged city streets without paying a cent” of those costs.