Impending Box Impact Warning System for Prevention of Snowplow-Bridge Impacts: A Final Report of Investigations

Each year, three or four Mn/DOT snowplows suffer bridge/box collisions while plowing. These collisions can shear off the box and frame damage to the truck. The box then falls onto the road surface where it becomes an immediate life-threatening hazard to traffic. In some cases, the integrity of the bridge may also be compromised. A typical collision of this type requires expenditures of $30,000 to $40,000 and results in potentially dangerous delays in achieving clean pavement status along the affected snowplowing route.

Feasibility of linking on-board GPS technology for Automatic Vehicle Location with the current bridge information database at Mn/DOT, "BrInfo," will be investigated, on a plow-route by route basis, to create collision maps. Collision avoidance then will use some primitive form of map matching. In addition, a prototype warning system that serves as a bridge proximity sensor will be developed to alert the snow plow driver that he/she is approaching a bridge with the box at a dangerous height. This warning system is integrated in an on-board box position sensor so that the driver can be alerted that the box must immediately be lowered. While realizing that additional means for box height control may complicate snowplow maintenance, any system that relieves the driver of cognitive overload, to reduce driver stress and fatigue during plowing operating, when running extended rural plow routes, needs to be implemented.