Police said the 56-year-old woman was driving very slow between the shoulder and the right lane just before the 1:20 p.m. accident. The driver of an 18-wheeler hauling cars tried to avoid the car, but a portion of the truck's pipe impaled the car, killing the woman.

The name of the victim had not been released pending notification of relatives.

Police said they don't know why the woman was driving so slow.

The truck driver, Jonathan Strahan of Denham Springs, was not injured. No charges are expected to be filed, police said.