Link Vehicle-Count—the Missing Measurement for Traffic Control

More effective and simpler solutions of many traffic control problems would become available if one could measure in real time the number of vehicles and the time they spend in various links of the road network. A technology based on vehicle re-identification is presented for the real-time measurement of link vehicle-count and link travel time. Extensions of the approach can also estimate turning movements. The solution to old and new control problems for freeway and urban street traffic is described.