Lyft Shuttle is the ride-hailing industry’s latest product to mimic the fixed routes and flat fares of a city bus service. The new feature, which is being tested out in San Francisco and Chicago, is an extension of Lyft’s carpool service, Lyft Line.

But rather than arriving directly at your door and then dropping you off at your exact location, the driver operates along a fixed route, with predetermined pick-up and drop-off locations. So people using the service may save a little money on fares, but they’ll also have some walking to do.

The service is only available during weekday commute hours, from 6:30-10AM and 4-8PM. Fares for the trips are also fixed “at a low price point,” a spokesperson said, but the price is still determined by time and distance. Fares for Lyft Shuttle are not effected by surge pricing (or as Lyft calls it, Prime Time).

We don’t have specifics on prices and how it will run exactly — for example, do drivers just cruise the routes waiting for hails, or do they swing by specific locations every few minutes like a bus — with Lyft promising to reveal more details in the future.

Riders who choose to use the service are being offered a discount until April 30th. Drivers are paid the normal Lyft Line commissions, unless surge pricing is in effect. That’s when Lyft will have to dip into its own piggybank to cover the difference with subsidies.

“Lyft Line is the future of rideshare, and we often test new features that we believe will have positive impact on our passengers' transportation options,” a spokesperson said. “We look forward to feedback on Shuttle from the Lyft community; we see a number of commuting use cases that this mode will make easier.”

This is not a new concept in the world of ride-hailing apps. Uber and Lyft have been testing various fixed-route products for several years now. In 2015, Uber began testing a service called Uber Hop in Seattle, in which multiple riders who are traveling a similar route are paired with the same driver. This was modeled on the discounted "Smart Routes" Uber was testing in San Francisco and Chicago earlier that year.

Lyft had a more casual carpooling product that it was testing in the Bay Area, in which non-professional drivers could get paid to pick up strangers on their way to work. But that pilot was shut down after Lyft failed to find enough drivers to join.

If Uber and Lyft continue to convince more people to share rides and use fixed routes, and the companies' automatic routing systems grow more precise, it's easy to imagine a future where a fleet of minivans or charter buses use Uber and Lyft's platforms and transport herds of commuters to and from work every day, alongside subways, buses, dollar vans, and other modes of transportation.