Uber is allowing riders to hail vehicles run by a national paratransit company, to increase the number of wheelchair-accessible vehicles available in Philadelphia.

Since July, MV Transportation vehicles have been taking requests for rides through the San Francisco-based tech company's platform. Uber won't say how many wheelchair-accessible vehicles are now operating in the Philadelphia region, saying only that there now is three times the volume of service and that the average wait time in the city is slightly more than 12 minutes. The state requires a minimum of 70 wheelchair-accessible vehicles operating in Philadelphia between Uber and Lyft.

The contract allowed MV Transportation to also offer service through Uber in New York City, Boston, Washington, Chicago, and Toronto. MV Transportation is expected to begin partnering with Uber in Los Angeles and San Francisco in 2019.

"We are invested quite heavily in this," said Uber's Malcom Glenn, who leads efforts to improve the company's accessibility in underserved communities. "In the first year, we are likely to spend tens of millions of dollars on this."

Under the contract, MV Transportation recruits, pays for, and puts drivers through the training needed to be eligible, Glenn said. Uber continues to allow other drivers with accessible vehicles to provide service to customers in wheelchairs.

The improved service has been noticed. "The last couple of times I rode Uber, my wait was under 10 minutes," said Theresa Yates, who uses a wheelchair. "Previously I had to wait 15 to 20 minutes."

She noticed speedier service on a recent trip to Magee Rehab. On another trip to Montgomeryville to get repairs to her wheelchair, she had no trouble taking an Uber there, but the return trip was complicated when a driver didn't show up for 20 minutes and didn't respond to calls, she said. She canceled the ride, she said, and ordered another without trouble.

She uses Uber at most two times a month, she said, when bus travel is impractical.

Lyft, too, has partnered with private companies to aid disabled customers, specifically through a contract with a company that provides assistance to people who are blind or visually impaired, a spokesperson said.

Public transit for people in wheelchairs has been an ongoing challenge in Philadelphia. SEPTA's bus fleet is fully accessible for wheelchairs, but recently a woman in a wheelchair was unable to board a bus because a passenger wouldn't vacate the area where wheelchairs can be secured. There also have been complaints about drivers who won't stop when they see a person in a wheelchair at a stop.

SEPTA operates a paratransit service, but reservations for a ride must be made 24 hours in advance and travelers must accept a 30-minute window within which the ride may show up. In Boston, the Massachusetts Bay Transportation Authority contracted with  Uber and Lyft to supplement its paratransit services, but Uber's contract with MV Transportation represents a step beyond using a public transit agency as a middle man. Uber does not intend to compete with public agencies, Glenn said.

"We look at MV as a supplement to existing options," Glenn said.

MV Transportation did not return a call for comment Tuesday, and it was not clear whether the company hired drivers or bought additional vehicles to fulfill the contract with Uber. According to Uber's statement, MV operates in 30 states, and in this region, it is one of three companies contracted to provides paratransit services for SEPTA. Its most recent agreement with SEPTA, which went into effect in September, was for nearly $41 million for five years of paratransit services. SEPTA did not anticipate MV Transportation's contract with Uber would interfere with its own service.