TRAFFIC OPERATIONS, HIGHWAY SAFETY, AND HUMAN FACTORS

This paper seeks to explain how the traffic operator currently aspires to the goal of safely and efficiently moving traffic, and offers some thoughts about areas for further human factors research. It begins with a discussion of the traffic operations framework. Each component of this framework is briefly discussed, including the highway system, travel demand, and system performance. This is followed by a discussion of the fundamentals of traffic flow. Both uninterrupted and interrupted flow are examined. Next, the tools which are available to assist the traffic operator in the tasks of providing more capacity and reducing demand are examined. The potential of Intelligent Vehicle/Highway Systems (IVHS) as a promising approach to increasing capacity and reducing demand is discussed. In conclusion, a list of questions that are yet to be answered about the effective and efficient use of many present-day traffic operations techniques is provided. These questions relate to (1) driver attention in congested traffic situations, (2) rubbernecking, (3) turning movements at intersections, (4) car-following behavior, and (5) the impacts of IVHS technologies on highway users.