Systems can be done are done entirely with one method only, or a system layout can benefit form both types of traffic control known as a combination control traffic management system. There may be long runs in which forward sensing control can be used reducing the expense of the traffic management system significantly. In the remaining areas of the path where there are divergence path and convergence path areas, a form of zone control would be used. The vehicles would respond to both types of traffic control depending upon the area in which they are operating.
