States of Traffic Flow in Deep Lefortovo Tunnel (Moscow): Empirical Data

The paper presents a preliminary analysis of traffic flow data collected in the Lefortovo tunnel located on the 3-rd circular highway of Moscow. It is shown that the observed tunnel congested traffic in fact exhibits cooperative phenomena in vehicle motion, namely, there is a region of widely scatted states on the fundamental diagrams which is related typically to the appearance of synchronized traffic. Besides, the spatial autocorrelations in the occupancy, vehicle velocity, and flow rate measured by different detectors are found to be essential. Especially it concerns the correlations in the velocity and occupancy, their correlation length gets values about 1 km. The phase portrait of the vehicle ensemble dynamics on the occupancy-velocity plane is also studied. It is demonstrated that there are two substantially different region on it. One matches actually the cooperative vehicle motion and contains some kernel where the dynamics is pure chaotic. The other part of the phase plane corresponds to the irreversible stage of jam formation.