About the research
As traffic volumes increase above the roadway capacity, traffic backups occur. These backups typically begin just prior to the merge point and grow until the volume through the work zone is less than the volume approaching the work zone. The ROADHOG sensors detect the presence of traffic backup prior to lane closures at work zones by the decreases in the speed and headway and increases in the volume and lane occupancy. Based on the preset system parameters, the RPU then activates display devices to provide visual warning to approaching motorists. By providing drivers with advance warning, it is assumed that traffic will approach the end of the queue more cautiously, avoiding high speed rear-end collisions.