Exceptional SCRIM®

A road survey vehicle that measures the skid resistance of the road surface has been rated as ‘exceptional’ by the US Federal Highways Administration.

The SCRIM® road survey vehicle manufactured exclusively by a road risk assessment and road surveying company W.D.M. Limited at its base in Bristol, United Kingdom, has just successfully completed a trial in six US states.

The SCRIM, the first road surveying machine to be built for use in the Unites States, has been marked in the FHWA’s interim report as ‘exceptional’ for its quality.

WDM® built the SCRIM on an American Volvo chassis and it was operated in the US by Virginia Tech Transportation Institute to research alternative technologies in identifying skid resistance characteristics.

The data it collected over 4,000 miles of testing was analyzed at the Turner-Fairbank Highway Research Centre in McLean, VA, and the FHWA’s report said the vehicle’s ability to meet regulatory compliance was ‘very good’.

Contracting Officer, Dan Confer, said: “Given what I know today about the contractor’s ability, I would recommend them for similar requirements in the future”.

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WDM® built the very first SCRIM in 1967, which means it’s now celebrating its 50th anniversary. Since then WDM®, the sole licensed manufacturers, have produced more than 80 road survey vehicles, operating to provide road risk assessment in 18 countries worldwide.

The SCRIM has test wheels mounted in the wheelpaths at an angle of 20 degrees to the direction of travel. The freely rotating smooth pneumatic tire is applied to the road surface under a known load and a controlled flow of water wets the surface immediately in front of it. When the road survey vehicle moves forward the test wheel slides across the surface and the force generated by this action is related to the wet skidding resistance.

The FHWA said that during the US trial the SCRIM met, or exceeded, all requirements, within budget and the systems engineering was also ‘excellent’. The European testing system had to be adapted to US standards, using high precision GPS, a 12-volt electrical system, and pass safety and pollution standards for all 50 US states.

Dan Cofner said WDM® had provided excellent support and management throughout. The Company put the US SCRIM through calibration and verification tests at the UK’s Transport Research Laboratory (TRL) and worked with the Virginia Tech Transportation Institute to train four road surveying operators. They also provided advice on any repairs and modifications for US roads and, as a result, the trial was completed four months ahead of schedule.

WDM® is a world leader in delivering safer road surfaces, with a global reputation for innovation and expertise in road risk assessment. They employ 150 people and are the UK’s leading manufacturer and provider of road surveying, highway maintenance and road risk assessment.

The Company also has offices in New Zealand, where it has been the primary provider of road surveying services to the New Zealand government for more than two decades. Two SCRIM vehicles are based in New Zealand and have helped deliver reductions in skid resistance related fatalities of up to 40%, as well as a cost/benefit return of 35 to one.

WDM® Chairman, John Gardiner, said: “SCRIM has been successful because it delivers reliable and reproducible data and enables highway engineers at both national and local level to target where to spend their budget most effectively." 

“The FHWA’s interim report recognizes the high standards we set out to deliver and we hope it will lead to further opportunities.”

USA: Registered in the US Patent and Trademark Office

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