Discrete Models of Traffic Flow (5-6)

Alternative Models 6

Flow Graph of NCS Model (2)

In order to supply a stronger evidence to support the current claim, we make direct comparisons between the flow diagrams of the standard model and Nishimura model.

Standard \rho=0.30

Standard \rho=0.33

With the standard Nagel-Schreckenber approach, absolute jamming blocks appear and propagate backward, and ocasionally disappear. the reason of the disappearence is in the random deceleration which leads to the absence of incoming cars to a jamming bock and could cause its percolation.

NCS \rho=0.30

NCS \rho=0.33

With Nishimura model, on the other hand, the existence of slow jamming blocks, seen as lighter blocks, in addition to the darker absolute jamming blocks is clearly observed.

A slow jam can percolate, turns into an absolute jam. Also an absolute jam can percolte, or turns into a slow jam. In other words, jamming blocks with various inter-car distance are all metastable and coexist with mutual conversion in Nishimura model. This is the physical content of the intermediate "third phase".