Check the signs, crack the gridlock

6 May 2005

Wireless technology will be deployed along with giant display screens as part of a novel approach being taken by the National Roads Authority aimed at freeing up travel times on one of the most heavily trafficked roads in the country: the N7 between Rathcoole and the M50.

The NRA initiated a pilot scheme to provide travel time information to motorists using the N7 to help them make strategic decisions on their journey.

“The NRA is committed to providing information to motorists as part of the European framework called Streetwise,” explains David Laoide-Kemp, ITS project manager at the NRA. “As the road network along the N7 didn’t have any cable ducting or fibre-optic cable, we needed to find a wireless solution to carry the information back to the central processing system at Dublin City Council.”

As part of the plan, non-intrusive radar-based traffic counters are mounted on poles at the roadside at 500 metres intervals between Rathcoole and the M50 on the northbound carriageway of the N7. Proxim MP11 systems from Bandwidth Telecommunications take the information back to the central processing system from the individual units. The counters collect vehicle speed, traffic volume and lane occupancy data from vehicles travelling on the N7 northbound and send this data back to the NRA’s traffic management system every 60 seconds.

The NRA’s traffic management system for the project, known as Advanced Traffic Management System (ATMS), then applies an algorithm to the traffic data to calculate the current travel time. The system sends this travel time information to electronic message signs on the N7 and also to a website at

There are two message signs used for displaying travel time information, one trailer-mounted sign located before Rathcoole and one fixed-cantilever sign located at the weigh station after the Rathcoole interchange. These signs display the estimated travel time to the journey from the sign to the M50 interchange at the Red Cow roundabout. In addition to calculating travel times, the ATMS allows operational staff at the Dublin Region Traffic Management Centre to enter traffic events such as accidents and roadworks into the system, and information about these events can be disseminated using the message signs and the website.

The next phase of the project, the installation of traffic monitoring and related field equipment on the M1 motorway between Balbriggan and the Dublin Port Tunnel, is currently under way.

By John Kennedy

Pictured are Eamonn O’Donnell, managing director, Bandwidth Telecommunications; Paul Redfern, systems engineer of UK engineering company IBI; and David Laoide-Kemp, ITS project manager, NRA