On Monday night, the Montgomery County Police Department (MCPD) issued a traffic advisory following a serious single-vehicle collision on Northbound Great Seneca Highway at Mateny Road in Germantown.

The incident, reported at 10:35 p.m., has resulted in the closure of the northbound lanes, prompting officials to urge drivers to seek alternate routes and anticipate significant delays in the area. Montgomery County Fire and Rescue Service (MCFRS) arrived promptly at the scene, where one individual was found to have sustained serious injuries. The condition of the injured person and the circumstances leading to the collision have not yet been disclosed.

As emergency personnel work to manage the situation and clear the scene, commuters are advised to avoid the area and stay updated on traffic conditions.

TRAFFIC ADVISORY: A single-vehicle collision has NB Great Seneca Highway closed at Mateny Road. MCFRS on scene, one person with serious injuries.
The call was received at 10:35 p.m.

Drivers are encouraged to seek an alternate route and expect significant delays. #MCPNews pic.twitter.com/dQm7MGauq7

— Montgomery County Department of Police (@mcpnews) July 22, 2025