Highway worker killed in Beltway crash near Oxon Hill ramp

A highway worker setting cones on the St. Barnabas Road ramp was struck and killed on the inner loop of the Capital Beltway, turning a busy midday lane closure near Oxon Hill into a nearly five-hour shutdown.

Maryland State Police identified the victim as Robert Dempsey, 40, of Ellicott City. Troopers said Dempsey was outside his emergency work vehicle on the ramp from St. Barnabas Road to Maryland Route 414 shortly before noon Saturday, April 25, when a Mazda CX5 hit him.

The driver of that Mazda was identified as Joshua Anderson, 41, of Fort Washington. Police said Anderson was taken by ambulance to a local hospital for treatment. No other injuries were reported.

The Maryland State Police College Park Barrack responded to the scene, and the Maryland State Police Crash Team is leading the investigation. Charges are pending the outcome of that investigation.

Prince George’s County Fire/EMS, Prince George’s County Emergency Medical Services, and Maryland Department of Transportation State Highway Administration personnel also assisted. Lane closures stretched for nearly five hours on the inner loop at Maryland Route 414, near the St. Barnabas Road ramp, a point where Beltway traffic funnels through Oxon Hill and the southern edge of the county.

For commuters, the timing mattered as much as the crash itself. The shutdown hit a stretch of I-495 that carries steady traffic between Oxon Hill, Fort Washington and the major access roads feeding the county’s southern corridor. Even without further injuries, the collision left drivers facing a long delay on a road where a single crash can quickly disrupt traffic for miles.

The death also underscored the dangers faced by roadside workers who step into live traffic to protect others. Dempsey was out setting up cones for traffic control when he was hit, a task that depends on drivers slowing down and staying alert in tight merge zones like the St. Barnabas Road ramp. On this stretch of the Beltway, where work zones, ramp traffic and commuter volume regularly overlap, a few seconds can turn routine lane protection into a fatal scene.