Study shows that, these methods of the on-ramp control and the main variable speed-limit control can effectively relieve the highway peak traffic congestion.

The critical problem in highway systems was discussed, and action of the main variable speed-limit control of the surveillance and control system of highway was analyzed.

The control for speed limit on expressway is a nonlinear and time variable system, it is difficult to simulate with a mathematical model. A neuro-fuzzy network is proposed to solve the problem.