Traffic Management and Driver Information on Inter-urban Networks: OPERA in Scotland



Traffic Management and Driver Information on Inter-urban Networks: OPERA in Scotland

Authors

TARRY S, Oscar Faber, UK and MORIN J-M, ISIS, France

Description

This paper describes recent advances in the use of real time traffic forecasting and simulation tools to support network management decisions during incident conditions, which represent a growing proportion of the global time lost due to congestion.

Abstract

This paper describes recent advances in the use of real time traffic forecasting and simulation tools to support network management decisions during incident conditions, which represent a growing proportion of the global time lost due to congestion.

Managing incidents or unbalanced situations in real time in large and complex networks is a difficult task for a human operator, for many reasons. Reasons include, a lack of knowledge about traffic assignment, about traffic future evolution and likely impact of strategies, difficulty in managing message changes in addition to other tasks, lack of consistency and repeatability of strategies used, etc.

The Operation Support Systems described in this paper provide the operator with various data concerning the state of the road conditions, undertake time- series forecasts of traffic conditions and automatically devise and implement measures to improve the operation of the network.

The capability of forecasting future network conditions, taking account of current and/or expected (in the case of roadworks) incidents enables road users to be advised not only of the current, instantaneous journey time but of the forecast journey time. The forecast journey time is the time that will be expended by motorists before completion of their journey. In uncongested conditions, instantaneous and forecast journey times, but significant differences can occur during incident conditions, when rapid changes occur in the traffic situation.

The real-time operation tools described include the MITHRA module, for updating historic origin and destination matrices to accord with current and forecasted traffic volumes. These matrices, along with the assignment paths of traffic through the network are the basis for reconstituting current traffic conditions and then forecasting traffic conditions over a selected time horizon, using the SIMRES real time traffic simulation module.

When combined, the MITHRNSIMRES decision support tool provides a powerful basis for the calculation of journey time predictions and identifying the predicted extent of congestion. MITHRNSIMRES is currently being used on ASF Company's A7 and A9 motorways and the SAPN Company's A13 motorway, in France.

When SIMRES is combined with the real-time strategy selection module SELECT, the possibility then arises to determine appropriate driver information and guidance strategies to address current and/or forecast incident conditions.

This is the basis of the OPERA aid to decision tool, which has been developed to support operators within the National Network Control Centre in Scotland.

OPERA is able to:

* reconstruct current traffic patterns;

* predict future network conditions, including the impact of incidents;

* automatically generate VMS strategies; and

* display information on delays and route advice to drivers when alternative routes are available.

Publisher

Association for European Transport