Country / Region:
United Kingdom, Scotland, North Lanarkshire
Location of installation:
M8 Glasgow / west bound between junction 5 for Shotts and junction 6 for Newhouse
Application:
Fog guidance, surface water detection, incident detection and hazard warning
Astucia products:
Hardwired uni-directional studs and detector studs
Project Description
Astucia's Intelligent Road Studs have been fitted to a 3 kilometre stretch of Scotland’s busiest motorway as part of a national road traffic management system that has seen the introduction of the UK's first national traffic control centre in Glasgow and the deployment of a range of advanced intelligent transport systems (ITS).
Focussing on the need to find a flexible and cost effective alternative to the inductive loop as a means of monitoring traffic conditions, a 3 year search by the Scottish Executive and Faber Maunsell led them to Astucia's Intelligent Road Studs technology. The customer was also interested in ways of using new technology linked with traffic speed collection to provide feedback to road users of approaching hazards. A trial is now under way designed to provide a vehicle monitoring and hazard warning facility that integrated into the existing traffic information gathering network.
The trial site chosen was the approach to Junction 6 on the west-bound section of the M8, a busy and fog-prone route connecting Edinburgh to Glasgow. An average of 51,000 vehicles a day use this stretch road. (1)
Twelve 250 metre long strings of Astucia F series hardwired, Intelligent Road Studs (IRS), each fitted with 14 red Light Emitting Diodes (LEDs) for high brightness, were installed at 18 metre centres, between the hard shoulder and the inside lane on the 3km stretch of the westbound carriageway, providing a clear delineation that could be seen day and night, up to a kilometre away. The studs are constantly on and are automatically dimmed at night to reduce glare.
The detector studs deployed at 500 metre intervals in the centre of the lane, and they collect data on traffic speed, weather incidents etc., they are connected to a series of seven cabinets housing a fog sensor, the controller, communications and power equipment that have been installed in the verge through the site, adjacent to detector stud positions. All on-site communications are hardwired. An Ethernet connection via TCP/IP enables information to be transmitted between the roadside equipment. Each control unit is responsible for control of and communication with the detector studs and flush studs.
Algorithms determine the type and extent of alert required, before control units automatically relay instructions to the appropriate strings of Intelligent Road Studs. The activated studs flash to provide hazard warning to approaching traffic. The System performs intelligent queue tracking so that only the strings of studs upstream of any slow moving or stationary traffic are activated, as illustrated in the diagram below (orange dots indicated flashing road studs).
During periods of reduced visibility, a sensory unit built into one IRS sends an alert to the stud controller, which in turn sets the standard flush studs to flash at their highest brightness intensity. The LEDs can increase drivers’ forward visibility from 90m to 900m compared to traditional retro-reflective passive road studs. Additionally, the high brightness capabilities of the IRS enable them to operate during daylight hours.
"The whole concept of the M8 system", said John Phillips, Astucia's business
development manager, "is to provide motorists with advance warning of a hazard. The increased brightness guides motorists safely through the reduced visibility caused by the fog or mist and the studs flashing alerts drivers to a traffic jam or an accident further on."
Whilst the design chosen by the Scottish authorities is fully automatic providing round-the-clock reassurance to drivers, Astucia's technology can also provide a fully flexible system that allows for remote or on-site manual control or monitoring of traffic conditions.
The automatic system can be overridden by a switch within the roadside control cabinet, if an incident occurs outside the parameters set down for the system, a highways engineer or police officer may wish to trigger the additional brightness in the studs or cause them to flash.
Benefits
Following the installation of the system trial, evaluation is being carried out by Faber Maunsell. The results of the trials will be submitted to the Scottish Executive who will then consider introducing the system to other major roads in Scotland.
Throughout the evaluation period, Vehicle speed, flow, headway; and lane discipline is being assessed under various traffic and climatic conditions, with and without the Astucia Intelligent Roads Studs in operation.In addition, accident figures and traffic data is being compared for periods before and after the installation.
The performance of all system components and functions will be evaluated to identify operational issues and benefits. In fact the studs have now been installed since the end of 2003 and to date, they have proved to be robust and low maintenance.(2)
Faber Maunsell reported that: “The system is considered to improve safety overall. Full analysis of accident statistics has not been undertaken as there is not 3 years of post implementation data. However, the trial showed that when flashing the studs do result in a reduction in speeds, increase in headway and reduced lane change manoeuvres.” (3)
During the trial period specific tests were carried out for evaluation purposes Faber Maunsell reported that during one such test: “The results show that there was a small decrease in speed (3%), 13% change in headway and a 65% drop in lane changing – including an 81% drop in dangerous lane change manoeuvres.
It should be noted that the studs were tested in the worst case environmental conditions – dry sunny weather.
During these conditions, the studs are at their hardest to see and it is anticipated that the results would be even more impressive if the test had been undertaken in the hours of darkness.” (3)
Initial comments from the public have also been favourable such as: “The IRS have vastly improved from the previous studs and visibility is better; ‘Very useful when it’s poor weather – gives a degree of comfort’; ‘I’ve driven past these on the M8 about four times while they have been operational, and believe they will make a worthwhile contribution to improving road safety’; and ‘In my opinion as an HGV1 driver these road studs are a benefit to the driver”. (3)
The continuous digital information is downloaded via a GPRS connection to the motorway control centre. Data collection is already helping in the planning and management of the M8 network.
