It happened around 1:44 p.m. near the Gulph Mills exit in the eastbound lanes.
Police say Joseph McHenry of Drexel Hill, had just climbed over the center concrete median and was attempting to walk across to the right shoulder while carrying a filled gas can.
That's when he was spotted by Robert Clark of Downingtown who was driving a Toyota Tundra pickup that was also pulling a single axle trailer in the right lane of travel.
Officials say Clark immediately applied his brakes and began sounding his horn.
McHenry was struck by the Tundra and flipped over the hood and into the air, coming to rest in the right lane.
Clark stopped and called 9-1-1.
McHenry was rushed to Bryn Mawr Hospital, but died shortly after arriving.
The investigation continues.