HARRIS COUNTY, Texas -- Deputies say a man was speeding at about 100 mph when he slammed his Honda into an 18-wheeler, leading to his death.

Deputies were forced to shut down FM 1960 westbound at Walters Road just after 4 a.m. for several hours Wednesday, but the roadway has since reopened.

“That car was traveling at a very high rate of speed at approach of the intersection,” Investigator D. Drake, with the Harris County Sheriff’s Office, said.

Sheriff's deputies say the driver of the Honda was decapitated instantly after he crashed into the big rig's trailer.

The driver’s name hasn’t been released yet as investigators try to figure out why he was driving so fast.

“There was a witness that said he may of heard cars racing but other than that statement I don't have anything to substantiate that,” Drake added.

The driver of the 18-wheeler was not hurt.

Photos: Driver killed in violent crash on FM 1960