The accident took place around 2 am in the Northbound lanes of I-95 after Lorton Road prior to the Pohick Road overpass.
The tractor trailer was carrying a load of produce and struck the second truck which belonged to a Virginia Department of Transportation contractor as it placed reflectors on I-95 North. Fortunately the VDOT driver saw the tractor trailer bearing down on him and lept over a barrier to avoid being struck.
He did however sustain a broken arm. http://www.wtop.com/?nid=41&sid=2487630