The Long Valley First Aid Squad responded to the crash on the bridge over the South Branch of the Raritan River at Schooley's Mountain Road.
The squad had to remove the door of one of the vehicles using Holmatro Pentheon Tools to access one of the patients, one of three who required treatment, they said.
Two patients were taken to a nearby hospital with minor injuries.
Meanwhile, Morris County Roads and Bridges responded to conduct a structural assessment of the bridge as LVFAS provided lighting and ladder access.
The local fire company was also called to help clear a fluid spill.
The cause of the collision was not immediately clear.
The scene was cleared within about an hour and a half.
Click here to follow Daily Voice Parsippany-Troy Hills and receive free news updates.