Keep your distance from a slow-moving truck and pass only when you are certain it is safe. Large vehicles take longer to slow down. If you pass a large vehicle or make a lane change in front of one, leave extra room before you merge back in front of the vehicle. Make sure you can see the truck’s headlights in your rear‑view mirror before you reenter that lane, and maintain your speed once you get there. Never pass when you are approaching the top of a hill. You don’t know what hazards might be on the other side of the hill.