Ramp metering: a microscopic control approach

Abstract

In order to reduce congestion numbers on the highways, ramp metering can be used. The currently existing ramp metering control strategies are of a macroscopic nature. This means that the average occupancy on the main lane or average flow values on the main lane determine the temporarily fixed cycle times for the traffic light located near the on-ramp to control the inflow from the on-ramp. In this thesis, it is investigated to what extent a microscopic approach to ramp metering would lead to less travel time delays. This approach shows a green light for the on-ramp vehicles when a gap in the main lane flow on the right lane has been detected instead of using the temporarily fixed cycle times. Computations on the location of the gap measurement loop detectors is required. Therefore, an acceleration distribution has been composed by means of an experiment as well. Concludingly, it was found that the proposed microscopic algorithm leads to additional travel time savings in the base case scenario compared to the currently used Rijkswaterstaat algorithm. Furthermore, adjustments to the developed microscopic control structure, such as a combined Rijkswaterstaat and microscopic algorithm, are proposed and it is recommended for further research to implement these adjustment and investigate their effect on the travel time delays. (PS. The paper was included at the end)