Variable Speed Limits for Motorway Off-Ramp Queue Protection

Model predictive control for optimal coordination of ramp metering and variable speed limits

This paper discusses the optimal coordination of variable speed limits and ramp metering in a freeway traffic network, where the objective of the control is to minimize the total time that vehicles spend in the network. Coordinated freeway traffic control is a new development where the control problem is to find the combination of control measures that results in the best network performance. T...

Application of Variable Speed Limits and Ramp Metering to Improve Safety and Efficiency of Freeways

Research recently conducted at the University of Central Florida involving crashes on Interstate-4 (I-4) freeway in Orlando, Florida led to the creation of new statistical and neural networks models that are capable of determining rear-end and lane-change crash risks along the freeway in real-time. For determining the rear-end crash risk, it was found that rear-end crashes occur within one of t...

Effects of on-ramp and off-ramp metering on queue forming in urban traffic networks

To control the traffic flows near on-ramps and off-ramps, ramp metering installations can be used. We compare on-ramp metering and off-ramp metering, with respect to queue forming and total time spent. Both control measures are used to improve traffic flow on freeways, and both have influence on the route choice of the drivers. Although the two measures are very similar, there are some major di...

A Multi-hierarchical Motorway Ramp Signalling Strategy

Ramp signalling is an access control for motorways, in which a traffic signal is placed at onramps to regulate the rate of vehicles entering the motorway and thus to preserve the motorway capacity. In general, ramp signalling algorithms fall into two categories: local control and coordinated control by their effective scope. Coordinated ramp signalling strategies make use of measurements from t...

Assessing Safety Benefits of Variable Speed Limits