Emerging in-car communication technologies continually offer new communication capabilities between vehicles and infrastructure that, together with more accurate positioning systems, can be used to improve performance of current Intelligent Transport Systems through cooperative systems. The aim of this paper is to present a novel ramp metering strategy, exploiting cooperative systems to further reduce congestion at motorway junctions. This new system, called Cooperative Ramp Metering, rearranges gaps present in motorway traffic by requesting cooperation from participating vehicles in order to facilitate the merging of platoons of vehicles released by an on-ramp traffic light. The performance of this new system have been evaluated using microscopic simulation. Results indicate the reduction of late-merging vehicles, decrease of congestion occurrence and improvement in merging capacity. This study shows how the use of new cooperative systems can improve the performance of current ramp metering and lead to a reduction of congestion on motorways.