The BML traffic model is perhaps the simplest system exhibiting phase transitions and self-organization. Moreover, it is an underpinning to extensive modern studies of traffic flow. The general belief is that the system exhibits a sharp phase transition from free flowing to fully jammed, as a function of initial density of cars. The existence of this sharp transition has been cited in the scientific literature several hundreds of times.
Use your BML experiment to conduct a simulation study of the behavior of the BML model.
1. For what values of p, the density of the grid, did you find free flowing traffic and traffic jams? Did you find any cases of a mixture of jams and free flowing traffic?
2. How many simulation steps did you need to run before observing this behavior?
3. Does the transition depend on the size or shape of the grid?
To answer these questions, run the experiment for different values of the input parameters.For each set of input parameters that you examine, run the experiment multiple times tounderstand the variability in the process. For example, does a p = 0.8 always end in a traffic jam or does it only end in a traffic jam 70% of the time?