The Control of Traffic Flow to Increase the Flow

An operational study of tunnel-traffic flow is presented. A bottleneck within the tunnel is shown to cause shock waves which travel backward in the stream and continue to the entrance of the tunnel. Flow and density data at the bottleneck is fitted to a fluid model description of the flow. Analysis of the speeds of successive vehicles indicate that the speeds stabilize to where the resultant flow is below the maximum allowable flow at the bottleneck. This speed is such that shock waves develop. The control of the traffic input by platooning the entering vehicles is shown to eliminate the shock waves and allow higher flows.