MSc Thesis Proposal

New ramp metering strategy for solving freeway traffic jams

Mentors: A. Hegyi and B. De Schutter

Problem statement
Freeway traffic jams are often caused by excessive traffic from the on-ramps. To limit the amount of traffic entering the freeway often a traffic light is placed at the on-ramp, the so-called ramp metering (see the figure for an example). This traffic light periodically switches between red and green, and allows one vehicle per green to the freeway. By regulating the switching frequency the amount of traffic that enters the freeway can be controlled. The resulting improvement of traffic flow observed in practice varies between 0 and 10%, which is quite small.

Probably one of the reasons for this small improvement is that most ramp metering algorithms do not take explicitly into account the so-called capacity drop. The capacity drop means that the traffic flow leaving a traffic jam is significantly lower than the flow under normal free-flow conditions. The main consequence of the capacity drop is that the traffic flow cannot be restored to the higher pre-jam flow as long as the traffic jam exists. Therefore, the ramp metering algorithm should explicitly aim at removing the jam. However, existing algorithms do not explicitly take into account the existence of the jam, but mainly aim at the prevention of traffic jams. Goals
The goals of this MSc project are:

Illustration of ramp metering and capacity drop.

Illustration of ramp metering and capacity drop.



If you are interested in selecting this project as your MSc project, please come along or send us an email for more information.


This page is maintained by Bart De Schutter.