Basically yes, but at least one system I know of is more sophisticated than that - it measures the rate of traffic joining the route, and the traffic already on it, and computes the best duration for the 'red' period. In this way it adapts to different degrees of congestion by behaving differently, therefore this type]/b] of control doesn't just move the jam somewhere else.kendor said:So let me get this right the traffic lights stop traffic joining the motorway, do they wait for a lull in the motorway traffic before turning green and allowing traffic on? otherwise there will still be congestion surely with traffic fighting to get onto the motorway?
Plus, since the filtering improves, the aggregate flow rate down the motorway increases, and the net effect on the locale is positive, not negative.