Phase transition and critical phenomenon in traffic flow model with velocity-dependent sensitivity

The traffic flow model with optimal velocity is extended to take into account the velocity-dependent sensitivity. The dependence of the jamming transition upon the sensitivity is investigated in the extended optimal velocity model. The phase transition among the freely moving phase, the coexisting phase and the homogeneous congested phase is studied by computer simulation. Order parameter S which is different from zero below the critical point is shown. The phase diagrams are obtained for the sensitivity parameters depending upon the car velocity. It is shown that the phase boundaries and the critical point depend largely upon the sensitivity parameters. The scaling properties of the headway, the car velocity and the jam’s propagation velocity are found near the critical point. It is shown that the scaling exponents are independent upon the velocity-dependent sensitivity.