US ride hailing company Lyft has begun testing a new shuttle service as a part of its Lyft Line commuter ride sharing option.

As first reported by TechCrunch, Lyft Shuttle works like a bus route, operating along a set route with specific pickup and drop-off points. The trial of the service is currently running in San Francisco and Chicago.

The Shuttle only runs during regular commuting hours – 6:30am to 10am and 4pm to 8pm – and has a fixed rate fare, compared to Lyft’s normal pricing which changes depending on demand.

Users who are not nearby the test routes will not see any change to the Lyft app, but those in the vicinity of a route will be able to use Shuttle through the Line option on the app.

To use the service, users must have the latest version of the app. If near a route during commute hours, they will be able to toggle to Shuttle and book their place on the service. The user then follows the in-app directions to the nearby pickup spot. The service will also provide users with an estimate of how long the walk will be, how long the drive will be, and how long the walk will take from the drop-off point to their final destination.