The warning period has passed — as of Monday morning, drivers who pass a school bus that’s picking-up or dropping-off students in Fairfax County, Virginia will receive a $250 citation.

Announced in March, under the pilot program, 50 cameras have been installed on Fairfax County Public School buses to identify drivers not adhering to the stop-arm signals, which are extended when a bus stops to warn drivers that children are getting on or off the bus.

After a 30-day grace period, in which drivers received warnings, citations are being issued, as of May 12.

The county said in a statement to WTOP that last week’s violations were still being processed, but preliminary data shows the program is averaging 76 warnings per day.

When the bus comes to a complete stop and the stop-arm is deployed, the camera automatically detects vehicles that pass within the enforcement zone, recording video of the vehicle, its license plate and the extended arm. The images are reviewed by law enforcement before a Notice of Infraction is issued.

The county said the program may be expanded as the school system and police evaluate “the administrative process and effectiveness of the technology.”

In D.C., the fine amount for a school bus stop-arm safety infraction is $500. That’s double of what it would cost to violate the same law, if caught on camera in Fairfax County.

Stop-arm cameras began appearing on public school buses in neighboring Montgomery County, Maryland, in 2016 after a two-year pilot program there.

Several other D.C.-area school systems have at least some school buses equipped with cameras for automated enforcement, including Arlington County and Falls Church City in Virginia and Charles, Prince George’s, Washington and Frederick counties in Maryland.

WTOP’s Luke Lukert and Matt Small contributed to this report.