Observed Multilane Speed Distribution and the Kinetic Theory of Vehicular Traffic

Speed data on the multilane roadways of the New Jersey Turnpike have been obtained by means of aerial photography. The characteristics of these observed distributions have been analyzed in terms of the kinetic theory of traffic which involves three processes: “interaction,” “relaxation,” and “adjustment.” Comparison of various aspects of the theory with the data is made on the basis of the moments of the observed speed distributions through a process of calibration in terms of the parameters involved in the three processes mentioned. Using the moment method employed earlier, we report the first successful effort to calibrate all of the parameters in the basic model. Agreement between independent methods of calibration provides an indication of the validity of the kinetic theory of multilane traffic. A discussion is given of three different flow regimes: “individual,” “collective,” and “hydrodynamic” flow as well as of the discontinuity of flow in the concentration range of about 50–70 veh/lane-mile.