Buses in D.C. are now using cameras to deter people from parking or driving in bus-only lanes.

License plates on cars that use bus-only lanes may be captured on one of 140 bus-mounted cameras that travel on 31 routes. Under a new program that launched Monday, drivers of these cars will receive warnings via mail over a 45 day period. Starting Sept. 18, however, drivers may be fined up to $100 for unauthorized driving through bus-only lanes, or $200 for parking or standing in a bus-only lane. Drivers will not be fined during the warning period.

The program was announced in June and is part of Metro and the District Department of Transportation’s (DDOT) Clear Lanes Project, aimed at improving bus travel times. DDOT will be in charge of all enforcement.

In a statement Monday, DDOT Director Everett Lott said the initiative “will improve the accessibility and efficiency of our transit network.”

“Parking in a bus stop zone for even a minute can prevent the bus from being able to fully pull up to the curb, impacting the ability for bus riders using wheelchairs or mobility devices to board the bus,” Lott said.

Metro General Manager and Chief Executive Officer Randy Clarke called it a “significant step to creating a better bus experience.”

“By partnering with the District, we are helping to keep customers moving safely and reliably, while positioning Metrobus as one of the most sustainable and most cost-efficient ways to travel in DC,” Clarke said in a statement.

Metro projects that the initiative will improve service for more than 60 percent of Metrobus riders. Critics of the initiative, however, have raised concerns that the fines would disproportionately affect low-income drivers and have called for additional communication from the District to ensure more of the public is aware of the program.

Affected bus lanes include routes servicing H and I streets NW downtown, 14th Street in Columbia Heights, Martin Luther King Avenue SE, and Minnesota Avenue SE.