Traffic was down to one lane along Chestnut Expressway in Springfield this morning after a tractor-trailer crash.

The crash happened at Chestnut and Grant just before 5:30 a.m. Thursday.

Springfield police say the tractor-trailer was the only vehicle involved. The driver suffered a medical emergency, then crossed over into the westbound lanes of traffic and hit a sign.

No one else was injured. The driver was taken to the hospital.