PHILADELPHIA (CBS) - All lanes of the westbound Schuylkill Expressway were shut down Thursday morning near Conshohocken due to a jack-knifed tractor trailer.

The accident happened at about 5:30 a.m. near the Conshohocken curve and tied up traffic for nearly three hours. Lanes didn’t reopen until 8:30 a.m.

Traffic was at a complete standstill and traffic cameras captured many stuck drivers standing outside their cars and mingling with other drivers.

After police reopened the Expressway, some drivers ran out of gas and at least one driver had to woken up by a Pennsylvania State Trooper.

Many stalled cars clogged the flow of traffic after lanes were reopened and police even had to wake up one driver who appeared to have fallen asleep while waiting.

The cause of the accident remains under police investigation.

Stay tuned to KYW Newsradio for Traffic and Transit on the Twos for the latest information.

Reported by Al Novack, KYW Newsradio 1060