TULSA, Oklahoma - Northbound traffic on the west leg of the IDL to Sand Springs has been mostly restored after a tanker overturned in downtown Tulsa.

The truck overturned on the northwest corner of the IDL just before noon Thursday. The 5,000-gallon tanker spilled a cargo of roofing tar on the northbound lanes of the highway just behind the Tulsa County Jail. There is also oil and gas from the wreck on the road.

I-244 westbound, eastbound and northbound traffic was shut down for a couple of hours. 

"It's cooled down enough that it's starting to solidify, but we still have to clean it up. We can't leave it in the ditch and on the roadway," said Stan May for the Tulsa Fire Department

The spill poured out of the tanker and drained on the slope of the highway down the embankment just behind the Tulsa County Jail.

At first, the fire department was concerned the hot tar could ignite but as it cools firefighters said it becomes less dangerous and more difficult to remove.

"We know we've dumped close to a thousand gallons. The tank itself would hold 5,000 gallons, but we're not sure how much was in it when it dumped over."

The Highway Patrol said two people were in the truck but at first, it was unclear who was driving. Troopers eventually determined the driver who only suffered a slight injury.

His passenger was also hurt and taken to the hospital.

Troopers said the driver was not arrested or ticketed at the scene but the investigation was continuing.

Drivers should avoid the area as first responders work to clean things up. It's expected to be a long process as a lot of tar is covering the roadway. Currently, workers are spreading an absorbent material over the remaining tar which should allow them to scoop it up, but it could take several layers.