A Zohrabi, TRL Ltd, UK
The abstract presents the advantage of remote monitoring of motorways by developing applications for the fault finding and monitoring purposes and explains how these products helped to improve the performance of the M25 Controlled Motorways system.
The western M25 is one of the busiest sections of motorway in Europe carrying in excess of 200,000 vehicles per day. The Controlled Motorways Scheme on the M25 Junctions 10 to 16 is an automated variable speed limit system that has been developed by the Highways Agency. The scheme operates using the Motorway Incident Detection and Automatic Signalling (MIDAS) system. Controlled Motorways systems are designed to manage the increasing demands on the network and to keep people moving in a safe environment.
TRL has monitored the M25 Controlled Motorways section since 1995. Over the intervening period TRL has developed deep expert knowledge of the behaviour of the Controlled Motorway system and of the traffic flows it manages. This expertise includes knowledge, methods and a range of specialist tools to collate, present and interpret data.
With the focus on reducing congestion and improving journey time reliability, the "Operational Technology Support and Development of Network Tools" project was commissioned by the Highways Agency Traffic Technology South. The project involved:
1) Monitoring automated and manual signal and sign setting
2) MIDAS Health checks to identify faulty loop sites
3) Real-time notification to Regional Control Centres covering the appropriateness of any signs or signal settings
4) Direct support to the Regional Maintenance Contractors Management Consultant team to advise on faulty MIDAS equipment and provide specialist network operations management tools and
5) Development of automated network tools to facilitate monitoring such complicated systems as Controlled Motorways.
Development of automated network tools was an essential part of the project to ensure swift and speedy delivery of the other objectives mentioned above. The most utilised products used for fault finding and monitoring purposes during this project are:
a) MIDAS HC: This is a specialist graphical tool with features designed to aid in the analysis and visualisation of motorway traffic data with the intent of ascertaining how well the MIDAS loops are functioning. The software has been developed to meet the current challenges of locating and diagnosing MIDAS loop faults. It is aimed at traffic engineers, traffic officers, data supervisors and transport advisors working in the field of motorway traffic management, monitoring and maintenance.
b) Motorway Traffic Viewer (MTV): The Motorway Traffic Viewer is a data visualisation tool. It uses a database that contains information on the location of MIDAS loops, junctions and signal gantries along the motorway. It takes data collected by MIDAS loops and plots it, using the database as a guide, over a user-defined period of time.
The first year's monitoring results show a significant fault reduction in the number of loop faults on the section. Monitoring of the MIDAS loop faults and signal/sign settings took place remotely from TRL by using the MIDAS HC and MTV. Prioritising the faults (so that the most important faults are given the highest priority for repair) has proved to be resourceful. Prioritising loop repairs is crucial as some loops are drivers for the settings of the signals and they should be dealt with immediately. As a result of this, the performance of the signals and signs also improved significantly. Notifying the Control Centres by the means of detecting and reporting any inappropriateness of the signal and sign settings has reduced the number of incorrect settings of speed limits and messages displayed on the road due to the manual and equipment faults.
Association for European Transport