Steer car
A specialized escort that helps physically steer the rear trailer axles on extreme loads.
On very long or heavy moves, a steer car carries an operator who controls the rear steering axles of a trailer (or coordinates closely with a rear steersman) to get the load through tight turns and intersections. Steer work is a higher skill level than standard escorting and usually carries a higher rate — often a per-mile premium plus an added daily flat.