The Ride On Flex bus service lets riders use an app to call for a small bus. The aim is to get more cars off the road and offer another way to get around for just $2.

Starting Wednesday morning, residents in Maryland’s largest county will have a new, low-cost public transportation option available to them — the D.C. region’s first on-demand public transit service.

At 10 a.m., the Montgomery County Department of Transportation will launch a pilot program for the new Ride On Flex bus service. Ride On Flex will run on-demand buses between designated areas in Montgomery County, specifically the Rockville and the Glenmont/Wheaton areas, according to the Montgomery County Council.

The Rockville service runs Monday through Friday from 9 a.m. to 3:30 p.m., while the Glenmont/Wheaton zone runs from 6 a.m. to 9 a.m. and from 3:30 p.m. to 7 p.m.

Buses are called using the Ride On Flex app, which is available for free for Apple and Android devices. During the pilot program, there will be a standard fare policy that will guarantee that riders will not pay more than $2 per ride. Riders can pay cash, use SmarTrip cards or bus passes.

After a rider requests service, he’s given an estimated time for pick up and drop off and is given a pickup location.

The service will connect residents with transit hubs, commercial centers and public services.

“The Flex service holds tremendous promise not only for taking cars off our roads, but also improving equity for residents who need an affordable solution for getting around quickly,” Montgomery County Executive Marc Elrich said.

Ride On Flex buses differ from the county’s larger Ride On buses. The smaller buses will carry up to 11 passengers, are wheelchair accessible and offer free WiFi.

“In Glenmont/Wheaton, we hope to see residents using Flex to fill first mile/last mile gaps in their daily commute,” county transportation director Al Roshdieh said. “In Rockville, the service lends itself more toward daytime errands and trips.”

The Ride On Flex app was developed in partnership with ride-share company Via.

“This technology makes for quick and efficient shared trips without lengthy detours, or inconvenient fixed routes and schedules,” said Daniel Ramot, CEO and co-founder of Via.

During the pilot program, the transportation department will monitor trip data and user feedback to judge how the service is performing.

Area transportation officials will watch to see what can be learned from the new service.

See the zones Ride On Flex serves.