Approach

•  Macroscopic model of traffic flow by means of the fundamental diagram of the road (speed-volume curve or volume-occupancy curve).

•  Representation of the data model on the equipped sections by an irregular grid of measures.

Traffic mapping on the A7 motorway

•  Gridding methods adapted to the configuration of each network (inverse distance algorithm).

•  Mapping congestion contours on state traffic variables (occupancy, density or speed).

•  Development of a traffic congestion observatory: automatic calculation of the characteristics of the traffic peaks detected (duration, length, congestion index, intensity).

Example from the traffic congestion observatory

Results and examples of applications

•  Functioning of infrastructures in urban and suburban zones (e.g. Paris ring road, A1, A6, A13, A7, A9 motorways).

•  Quantification of seasonal traffic peaks: (e.g. holiday departures on a toll motorway network).

•  Traffic operations (e.g. access control, VMS information systems).

•  Geometric modifications (e.g. impact of narrow lanes on A6, A3-A86, rush hour lanes on A4-A86).

References

[1] Cohen S., "Effect of narrow lanes on the capacity of motorways: a trial in the Paris Region" Proceedings of the Third International Symposium on Highway Capacity, Copenhagen, vol. 1, pp 337-349, June 1998.

[2] Cohen S., "Assessment of traffic operations on motorways: a numerical mapping approach", 8th World Conference on Transport Research, Antwerp , July 1998.