The crash occurred around 7 a.m. at mile marker 28.3.
Officials said a vehicle ran into the back of and under a parked tractor trailer.
Three patients were transported from the scene to Cooper Hospital, all in serious condition, one by helicopter and two by ground, according to police.
Crash shuts down westbound Atlantic City Expressway
State police initially diverted traffic off of the expressway at Exit 28. As of 9:20 a.m. officials report that one lane is getting by the accident
Officials reopened all lanes of the highway around 11:20 a.m.