Safer Driving, Smoother Flowing Traffic

A British automatic incident detection solution has been chosen for a four-year Framework contract by Sweden’s Trafikverket. Vibeke Ulmann spoke to Dr Stephen Clark, Navtech’s Technical Director, about ClearWay’s emergence as a ‘de facto’ AID standard for vital road and tunnel applications

Navtech Radar is a leading innovator and award-winning designer and manufacturer of commercially deployed radar solutions. The company’s patented designs have been shown to be high performance, robust and reliable. All Navtech’s solutions are based on high frequency radar technology, which provides reliable, cost effective detection  with a low false alarm rate – over long distances – in all weather and lighting conditions. The company’s radar detection solutions have been integrated with a range of control room operator interfaces, SCADA and 3rd party cameras. The radar themselves are small, lightweight, and low power, bearing little resemblance to larger radar that are generally found in airports or on ships.

Over the past five years, the Navtech’s ClearWay Automatic Incident Detection (AID)solution has been implemented in a variety of traffic management applications. After pilot installations for the hard shoulder lane running initiative on the M42 motorway near Birmingham in the UK, ClearWay was chosen for the 1.8km (1.1 mile) Hindhead Tunnel on the A3 in Surrey. With six radars in each of its twin bores, the tunnel is a key element of the 6.5 km (4 mile) stretch of new road that completes the dual carriageway link between London and Portsmouth.

“The Hindhead Tunnel project is a market leading application that has generated a lot of interest from road authorities,” explains Stephen Clark. “The Nordic countries were especially quick to see the benefits of using ClearWay in their traffic management applications and, in 2010, we were contracted by the Swedish Roads Authorities, Trafikverket, to test ClearWay at two test sites around Stockholm – the Södra Länken Tunnel and a stretch of the E4. Deployment onto a 16km stretch of the E4 south of Stockholm followed shortly afterwards in late 2011.”

“Although this section of the E4 motorway is all-lane running, it is still prone to congestion and accidents are common. In the absence of a hard shoulder, a reliable and accurate incident detection system is vital to quickly alert managers in Trafik Stockholm, the central control for all traffic around greater Stockholm. Traffic movement on the E4 is made even more difficult in the winter due to heavy snow, fog and low visibility. As well as rapidly detecting incidents in these conditions, Trafik Stockholm’s control centre also wanted a solution that would provide early detection of stopped vehicles, pedestrians and debris, particularly during times of low density, high speed traffic.”


The ClearWay solution offers 360 degree scanning capability within a radius of up to 500 metres and can detect a person walking on the hard shoulder or debris in the road as well as slowing or stationary cars. The solution is not affected by adverse weather conditions and has an extremely low false alarm rate – typically one per km per 24 hours.

Clark continues, “Although Trafik Stockholm’s principal objective was for an all-weather, long-range stopped vehicle detection system with a very low false alarm rate, a number of other requirements were set out, including the ability to detect congestion during rush hours. Therefore, we established a set of speed thresholds, which identify slowing vehicles, flags this up in the control centre, and allows the operator to generate Variable Messaging Sign (VMS) messages to warn drivers to slow down and/or of queues ahead. Because radar has a longer range than other technologies, we were able to demonstrate that ClearWay offers infrastructure savings for surveillance and incident detection and virtually eliminates maintenance, as the radars are unaffected by rain, snow, fog or changing sunlight levels.”

ClearWay’s successful deployment over 16km of the E4 motorway led directly to Navtech Radar being awarded a four year framework contract with Trafikverket for further implementations throughout Sweden. The initial contract is for two years with a two-year extension, awarded one year at a time. The next project involves a section of the E4 motorway north of Stockholm towards Arlanda International Airport.

It’s not just the Swedish roads authorities who have discovered that there are huge advantages and savings to be realised by implementing ClearWay AID solutions. Further motorway stretches in the northern part of England are in the pipeline and trials are due to commence on other European motorways later this year.

The Norwegian Road Authority- Statens Vegvesen – has also taken a keen interest, leading to the implementation of a 24-radar Navtech AID solution at the Mastrafjord and Byfjord subsea road tunnels near Stavanger. This new ClearWay AID application was designed by one of the three largest ITS consulting firms in Norway, Multiconsult, which presented a paper on the choice of ClearWay at the 2nd Tunnels and ITS Symposium in Bergen, Norway, in September 2013.

According to Stephen Clark, “Multiconsult started evaluating a Navtech AID solution early in 2012. After a site visit to the Hindhead Tunnel, they specified ClearWay AID for the refurbishment projects of both of the Byfjord and Mastrafjord tunnels. One of the key requirements was AID capability in very harsh weather conditions of snow, rain and fog. It is also particularly important to have AID capability around the tunnel openings where sunlight can create problems for drivers. They also needed a low-maintenance solution throughout the tunnel with a very low rate of false alarms and ClearWay is ideally suited, typically giving only one false alarm per km per 24 hours.”

All 24 radars plus Navtech’s sophisticated analytical software, Witness, were integrated into the SCADA solution in the control room by Bergen-based systems integrator, Trafsys. Working with Mesta, one of Norway’s leading contractors engaged in the construction, maintenance and operation of onshore infrastructure, the Navtech AID solution was installed in three phases during the autumn of 2013. This comprehensive, radar-based solution will be presented to Statens Vegvesen in spring2014.

“We’re incredibly pleased to note that our radar-based AID solution has been adopted as a ‘de facto standard’ in many countries,” says Clark. “In particular, the Nordic countries have introduced the technology very successfully and the Mastrafjord and Byfjord tunnels are prime examples of recent projects that have embraced our technology.”

Norway has more than 1,000 road tunnels, including the world’s longest – the 25km Laerdal tunnel. Based on the successful implementation at Mastrafjord and Byfjord, Statens Vegvesen has tasked Oslo-based Vianova Systems to conduct a feasibility study to investigate the possibility of making ClearWay the standard for AID in all applicable tunnels in the country over time. A comprehensive report is expected during the summer of 2014.

“We are strongly focused on the continued development of our radar technology,” Clark explains. “One of the results is the CTS350-X Radar, which we will launch at the Intertraffic Show in Amsterdam, from 25th to 28th March 2014. The CTS350-X is significantly smaller and lighter than previous models and easier to install and commission into service. It is still very effective – single radar can cover up to a kilometre of motorway, over multiple lanes.”

“The increasing adoption of our radar-based AID solutions also means that our manufacturing volumes are increasing. We are determined to use our increased purchasing power to make our new radar, like the CTS350-X, even more cost effective. For applications where fast and accurate detection is a must, such as multilane running on strategic roads with no hard shoulder, and in geographical regions where inclement weather is common, there are no other technologies that would be effective.”

The new CTS350-X ClearWay AID solution will see operational duty first in Sweden, on the E4 motorway link between Stockholm and the Arlanda International Airport.

Dr Stephen Clark is Technical Director of Navtech Radar