Abstract: A snowplow mountable on a track or similar vehicle includes a displaceable trip edge that enables the plow to pass over trip hazards without transferring significant impact forces to the plow. The plow mold board includes one or more trip plates that are coupled to the mold board through compression spring elements and linkages. The linkages cause the trip edge to swing up and away from the pavement to avoid "undercutting" when a trip hazard is encountered. This helps keep the plow from jumping. The linkage also automatically reduces the moment arm defined by the compression spring element, the trip plate and the mold board so as substantially to compensate for an increasing restoring force generated by the compression spring member as it is progressively compressed. The trip plate can thereby be displaced over its entire range without significantly increasing the contact force between the trip plate and an encountered trip hazard.