I was travelling and towing a boat on Interstate 55 heading North Bound while following a small car. We were about 1 mile West of Interstate 64 in Illinois, very close to St. Louis, Missouri. Beside the car was a Semi Truck who decided to make a lane change to the lane to his right. The car was beside the cab of the truck. As he began to change lanes, he was unaware of the car. he car attempted to move onto the shoulder but eventually the shoulder narrowed because we were on an elevated highway. Seeing that the car was running outta shoulder, the driver accelerated to try to get past the truck but was struck by the truck which cause a lot of damage. Fortunately, the young female college student was not injured and the driver of the truck was very professional and courteous towards the young lady. The truck driver freely admitted fault stating, "I didn't see the car at all, in fact, I thought I had blown a tire at first!"