Effect of density feedback on the two-route traffic scenario with bottleneck

In this paper, we investigate the effect of density feedback on the two-route scenario with a bottleneck. The simulation and theory analysis shows that there exist two critical vehicle entry probabilities alpha(c1) and alpha(c2). When vehicle entry probability alpha <= alpha(c1), four different states, i.e. free flow state, transition state, maximum current state and congestion state are identified in the system, which correspond to three critical reference densities. However, in the interval alpha(c1) < alpha < alpha(c2), the free flow and transition state disappear, and there is only congestion state when alpha >= alpha(c2). According to the results, traffic control center can adjust the reference density so that the system is in maximum current state. In this case, the capacity of the traffic system reaches maximum so that drivers can make full use of the roads. We hope that the study results can provide good advice for alleviating traffic jam and be useful to traffic control center for designing advanced traveller information systems.