For some on-ramps, which cause congestion on the motorway, it is not possible to install a ramp metering system for geometric or other reasons. But sometimes it is possible to meter traffic with the traffic lights of nearby intersections in such a way that the situation on the motorway improves and on the urban network the situation does not get worse. The research described in this article investigates the use of the traffic lights as metering lights and for this an algorithm was developed. The new control algorithm was tested for a virtual network in a simulation environment. The results show that metering with traffic lights is possible and has potential, but the effectiveness is less compared with regular ramp metering.
Taale, H., Hoogendoorn, S., & Legius, P. (2015). Metering with traffic signal control - Development and evaluation of an algorithm. In Transportation Research Procedia (Vol. 8, pp. 204–214). Elsevier. https://doi.org/10.1016/j.trpro.2015.06.055