A car and tractor-trailer collided on Interstate 81 in Luzerne County Monday morning. It happened in the southbound lanes around 11 a.m. near mile marker 172 in between the Pittston and Wilkes-Barre exits. Police say the driver of the car fell asleep, hit a guide rail, and then smashed into the trailer of the truck. No one was injured although the car ended up smashed under the side of the trailer. I-81 was down to one lane for about 45 minutes.