CENTREVILLE, Md. — Maryland State Police say a school bus driver has been charged with driving under the influence.

Authorities say 54-year-old Dale Clark Jr. of Chester was charged with DUI and related traffic charges after police received 911 calls from two motorists who reported an erratic driver Tuesday afternoon.

Police say Clark was the sole occupant in the school bus, which was traveling eastbound at Route 50 near Kent Narrows in Queen Anne’s County.

Responding troopers observed several traffic violations before stopping the bus on northbound Route 301 near Warrington Farm Lane.

Officials say Clark failed a field sobriety test at the scene.

The Queen Anne’s County School Board was contacted and sent a replacement driver to pick up the school bus.