HOUSTON -- All mainlanes of the South Loop East at Broad were shut down for several hours after a motorist slammed into a motorcyclist early Monday morning.

The accident happened at 1:14 a.m. The motorcyclist, who was not wearing a helmet, was traveling with three others when he was hit from behind. He was thrown from his bike, slid down the freeway and later died at Ben Taub Hospital.

The Honda Accord slammed into the guard rail, hit a light pole and knocked it into the other side of the freeway.

"[The driver] was not wearing a seatbelt, so he was ejected," HPD Officer Lloyd Thompson said. He was transported to Ben Taub Hospital in critical condition.

Police will test the driver to see if he was intoxicated.

"Anytime there's a fatality, the state does a mandatory blood draw, so we will get a test of what he has onboard, in his system," Officer Thompson said.

All lanes reopened around 5:40 a.m.