Innovative Solution Manages A ‘Gap’ In The Market

A combined road safety initiative which incorporates both tailgating and speed reduction warnings has been installed along Scotland’s A701on behalf of Transport Scotland.

Using a unique detection system to manage VAS (Vehicle Activated Signs), motorists travelling between Amisfield and the M74 will receive warning alerts via the illuminated signs when tailgating or driving above the appropriate speed threshold.

Drivers travelling too close to the vehicle ahead will be warned to leave a two second gap whilst speeding motorists will be warned of the correct speed limit for their vehicle, which varies in Scotland according to the different vehicle classes.

Chris Keenan, Clearview Intelligence’s General Manager Scotland who delivered the scheme in partnership with road operator Scotland TranServ, said: “Following a review of accidents over a five-year period, it was highlighted that tailgating and speeding were responsible for most of the incidents along this route. Through a single road safety initiative, we aim to tackle both of those problems and issue warnings relevant to the behaviour of the driver and their vehicle classification.”

The review discovered that vehicles travelling above the appropriate speed threshold was a factor in 73 percent of accidents – well in excess of the 50 percent average from the 2016 Reported Road Casualties Scotland report.

When it came to tailgating, cars and motorcycles were found to be the worst offenders with 26 percent travelling within two seconds of the vehicle in front compared with 17 percent of medium sized vehicles and 10 percent of HGVs.

Further investigation and surveys then found that on average, 89 percent of HGVs travelled above their 40mph threshold; 57 percent of medium sized vehicles travelled over their 50mph limit whilst 25 percent of cars and motorcycles exceeded the 60mph limit.

Vincent Tait, Scotland TranServ’s Strategic Road Safety Manager said: “We continue to work effectively with our supply chain partners, developing innovative road safety solutions that deliver real results and save real lives. Around the world authorities recognise the driver epidemic that is ‘close following’. This solution hits drivers directly, behind the wheel as they engage in this potentially life-threatening behaviour.”

Using detection technology to assess the gap, speed and classification of the passing vehicles, the system then prioritises the messages to be shown to the driver on the VAS. Key benefits of the system are the ease of the implementation by utilising solar power, wireless communication and passive safe infrastructure.

For those tailgating, the VAS will show a “too close, leave 2 seconds gap” message whilst speeding vehicles will be presented with the appropriate speed limit (60mph for cars, 50mph for medium vehicles and 40mph for HGVs) and “slow down” message. In incidents where a vehicle is both speeding and tailgating, the latter message will take precedence.

The predicted reduction in accidents will see a 55 percent return rate on investment within the first 12 months, based on Transport Scotland’s system of valuing the cost of an accident.

The inclusion of the tailgating message coincides with Highways England’s nationwide ‘space invaders’ initiative to encourage drivers to be more aware of leaving appropriate space between the car in front. According to figures released by Highways England, tailgating is a factor in one in eight casualties on the strategic road network and 87 percent of motorists had witnessed a vehicle driving too close to the vehicle in front.


The A701 scheme was built on the foundations of a similar project which was installed by Scotland TranServ and Clearview Intelligence along the A75 in March 2017 to deliver multi message VAS through vehicle classification.