State Police say the 40-year-old man from Royersford, who was shot in the head, died while in the hospital on Monday.
The suspected gunman, a 59-year-old man from North Dinwiddie, Virginia, took his own life.
Police say the gunman was driving in a white tractor-trailer and the victim was in a white flatbed truck.
The shooting happened last Friday around 1 p.m. on the Pa. Turnpike eastbound in Brecknock Township, near mile marker 291.3 between the Reading and Morgantown exits.
Anyone who may have witnessed the incident is asked to call police.