How will you navigate the world when you can’t drive anymore? You’ll have to wait years if you want to be chauffeured around in a self-driving car. A more immediate solution might be found in the thousands of drivers just an app-tap away through Lyft, Uber, and other digital-age transportation providers. But even these have their drawbacks.

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To start, less than a third of Americans over the age of 65 own a smartphone, a prerequisite for using an app. (It’s technically possible—but comparatively impractical—to preschedule a ride via a website.)

Seniors with mobility challenges might encounter another significant barrier: a lack of accessible cars. Uber offers a platform called UberWAV (for wheelchair-accessible vehicle) in 12 North American cities and another, UberASSIST, in 23 North American cities. UberWAV is supposed to match wheelchair passengers with vehicles equipped with a hydraulic lift or ramp. UberASSIST provides elderly or mobility-challenged riders with drivers who will help them into and out of a car.

But it’s easier to publicize a service than to deliver it. In October 2016, a disability-advocacy group in Chicago called Access Living filed a lawsuit in federal court asserting that Uber had failed to provide the broadly equivalent transportation options required by the Americans With Disabilities Act. Specifically, the suit claimed that over a four-year period, beginning in August 2011 when Uber arrived in Chicago, the company provided exactly 14 rides to customers who used a motorized wheelchair.

Uber issued a statement at the time saying that it was “committed to increasing mobility and freedom for all riders and drivers,” including the disabled. (In May, the Chicago mayor’s office announced a major increase in wheelchair-accessible transit options by making 50 wheelchair-accessible vehicles from Lyft, Uber, and VIA available within six months.)

UberASSIST, which relies on regular Uber cars, could be a boon to older adults who use a cane, walker, or folding wheelchair. But Uber doesn’t require or pay its drivers (independent contractors) to get UberASSIST training, and there’s no financial incentive for U.S. drivers to provide these rides, which may demand more loading time and door-to-door assistance. And when few UberASSIST cars are on the road, a driver may have to travel several minutes to reach a rider and then spend more time to help him or her into the car but can only start the meter once the passenger is buckled in.

Uber declined to specify how many UberASSIST vehicles may be available in any market in the U.S. A spokeswoman said the company is piloting different types of ASSIST models across the globe and that in many cities it’s working well. “We still have more learning to do before it is a widespread success,” the spokeswoman said.

Lyft and Uber have forged dozens of partnerships over the past year with senior residences, major health systems, and even the paratransit service of the Massachusetts Bay Transportation Authority. Last January Lyft debuted a “concierge” feature, which allows selected care providers to book a trip for a senior; Uber says it offers a similar service. These services have the potential to lower the cost and wait times for nonemergency medical transportation, but most passengers with limited mobility will still have to wait for their ride.

Editor's Note: This article also appeared in the July 2017 issue of Consumer Reports magazine.