Failing to check a blind spot is a primary cause of sideswipe collisions. This is common where one car switches lanes on an expressway but does not look in the car's mirrors or check the car's blind spot. If another vehicle is already in the lane the car intends to occupy, a collision is likely to result.
Often, this type of collision is called a lane changing crash. This, because it is due to a driver acting negligently while in the act of changing, moving, or adjusting lanes.