The lanes are part of an overpass that was closed three weeks ago when a dump truck crashed and burned on the New Jersey Turnpike below, killing the driver.
Only one lane was available for traffic headed toward Trenton.
Transportation officials say the other lane was closed "out of an abundance of caution."
But they say sophisticated load testing of the beams that support the overpass revealed the structure is safe for all vehicles on all lanes.
DOT crews removed the barriers that have blocked traffic from the lane once the evening commute concluded Tuesday.
The lane was back open well before Wednesday's morning rush.