Mix cooking grease with flour and you get gravy.

Mix about 500 gallons of used cooking oil with dirt on a heavily traveled road at rush hour and you've got a recipe for stalled traffic and a messy cleanup.

Traffic slowed for more than 4 hours Tuesday night while workers cleaned a grease spill that stretched about 600 feet along the southbound lane of Atlanta Highway in south Forsyth.

Capt. Jason Shivers of the Forsyth County Fire Department said the incident occurred about 4:30 p.m.

Shivers said a truck carrying several 250-gallon drums of used "nonhazardous, food-grade, cooking oil" lost some of its load just south of the Peachtree Parkway crossing.

"Even though it's a food-grade product, due to the quantity and fact it has impacted storm water runoff, it must be handled and removed in a proper (Environmental Protection Division) fashion," Shivers said.

The spill ran along the right hand side of the southbound lane, spreading into the storm drainage ditch in the right of way.

Shivers estimated that about 500 gallons spilled from the eight drums left behind by the driver of a truck owned by 13 Forks Cattle in Elberton.

The driver did not stop and could not be found after the spill, Shivers said. But one of the company's owners was contacted and came out to the site to assess the damage.

No one was injured in the incident. No charges have been filed, and officials haven't said if there will be any.

Shivers said the cleanup was the company's responsibility and required that an EPD-approved crew replace the dirt affected by the spill, wash the road and remove the oil from the drainage system.

Georgia Department of Transportation workers spread dirt on the spill Tuesday in attempt to contain it before the crew arrived.

Traffic was limited to one lane. Shivers said the road was cleared about 9 p.m.