The collapse happened Thursday afternoon where the highway crosses over Essex Avenue.
NJDOT said it is in the process of investigating the cause and monitoring the condition of the slope near the wall.
Steps are also being taken to further reinforce the slope, officials said.
Drivers were told to expect heavy congestion in the area and on Route 42 northbound as well.
"It's time-consuming, you know? It makes it hard to get where you have to go. There's no answer as of right now as to how long it's going to take to get fixed," said driver Evan Amato of Blackwood.
The wall is part of a nearly $1 billion road project called Direct Connection that will one day link several major highways with the goal of reducing traffic.
Right now The Direct Connection project is set to be completed by the fall of 2024.
NJDOT said it was not yet known if the wall collapse would impact that timetable.