The Tail Gunner serves as the eyes of the Road Captain. He watches the formation, and informs the Road Captain of any potential problems within the group. He watches other vehicles, and informs the Road Captain (and anyone else with radios) of hazardous conditions approaching from the rear, such as vehicles trying to cut into the formation and trucks passing with potentially dangerous wind blasts. He will watch for merging lanes, and will move into a merging lane (or stay in a merging lane just vacated by the group) in order to “close the door" on other vehicles that may otherwise find themselves trying to merge into the formation. At the Road Captain's request, the Tail Gunner changes lanes before the group, to secure the lane so the group can move into it.