Abstract: A truck tractor and removable body unit system selectively configurable as a tractor and freight box or an articulated truck-trailer combination includes a truck tractor having a frame supporting a drive axle and a steer axle with a fifth wheel mounted on the frame, and a body unit having a body mounted on a frame, the frame supported by a wheeled axle and having a king pin for releasably engaging the fifth wheel on the truck tractor. The body unit includes a coupling mechanism for releasably coupling the truck tractor frame to constrain lateral movement between the truck tractor and the body unit while allowing relative vertical pivoting movement between the truck tractor and body unit about the king pin and fifth wheel. An adjustable spring mounted to one of the truck tractor and body unit to act between the truck tractor frame and the body unit frame to adjust a loading between the truck tractor frame and body unit.

Abstract: A system and method for controlling navigation of a vehicle carrying hazardous materials includes a control module carried on-board the vehicle storing an information matrix containing hazardous material classifications associated with the identity and location of restricted sites. Each site and material pair has associated with it a control zone around it from which the hazardous material is restricted. The control module includes a positioning device that produces a signal indicating the vehicle's current position, which is compared to the coordinates for the control zones. If the vehicle crosses into a control zone, the system generates a warning to the operator. Further penetration causes the system to order a shutdown of the vehicle engine to prevent further movement.

Abstract: A truck tractor and removable body unit system selectively configurable as a tractor and freight box or an articulated truck-trailer combination includes a truck tractor having a frame supporting a drive axle and a steer axle with a fifth wheel mounted on the frame, and a body unit having a body mounted on a frame, the frame supported by a wheeled axle and having a king pin for releasably engaging the fifth wheel on the truck tractor. The body unit includes a coupling mechanism for releasably coupling the truck tractor frame to constrain lateral movement between the truck tractor and the body unit while allowing relative vertical pivoting movement between the truck tractor and body unit about the king pin and fifth wheel. An adjustable spring mounted to one of the truck tractor and body unit to act between the truck tractor frame and the body unit frame to adjust a loading between the truck tractor frame and body unit.