Czech government approves overweight truck enforcement WIM system


A weigh-in-motion (WIM) system technology from the German measurement technology developer Kistler has been granted type approval to monitor and help enforce the use of overloaded trucks on roads in the Czech Republic.

Following an assessment program, in May this year the Czech Metrology Institute (CMI) officially approved Kistler’s KiTraffic high-speed WIM system for use on the country’s highways to help prevent road damage. The system is already in use on the D7 highway leading from Prague to the Northwest, with the potential for the WIM technology to be used on other roads across the Czech Republic. Overloaded trucks pose a real threat to highways, with excess weight impacting on the road surface to a factor of four, according to the Fourth Power Law, which was discovered in the 1950s in the USA. In-road WIM systems for direct enforcement are now considered to be a convenient alternative to mobile scales for local and national authorities looking to impose fines for weight limit violations.

Kistler’s KiTraffic high-speed WIM system is comprised of Lineas brand quartz sensors integrated into the road, cameras, hardware and software. Fining overloaded trucks is made easy by weighing every passing truck at highway speeds. If a vehicle exceeds the weight limit, the KiTraffic system sends the exact weight and a photograph of the vehicle, including its license plate, to the road authority’s office. Employees can then research the owner in a national database and print a standard letter to fine the truck operator.

The company first installed the WIM equipment with the system integrator and local partner SPEL on a brand-new section of the highway D7. In December 2018, CMI visited the new site in order to witness the accuracy of the WIM system at first hand. The team first weighed vehicles from categories B (a VW transporter), C (a six-axle truck) and D (a bus) on stationary scales and then in motion via the high-speed WIM system. The maximum error margin permitted by CMI is 5% per vehicle and 11% per axle; a test the Kistler system passed without problems. The International Organization of Legal Metrology (OIML) and the Swiss Federal Institute for Metrology (METAS) had previously certified the KiTraffic WIM system, which helped facilitate its quick approval in the Czech Republic. Plans to open a further 15 WIM stations on Czech highways are already in place.

“Combined with our expertise in collecting and analyzing data from the sensors, our practical experience has allowed us to build a system that is very precise,” said Tomas Pospisek, Kistler’s global market development manager for road and traffic systems in the EMEA region. “All its components are streamlined and work really well together. The error margin is factored in by the system to make sure no vehicle is fined incorrectly. There is currently no Pan-European certificate for WIM systems. However, having already obtained a more general measuring certificate, the OIML helped us to get approved in the Czech Republic. This meant we were able to skip some tests and save time.”

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Adam joined the company in 1994, and has been News Editor of TTT since 2009. In his other role as Circulation Manager, he helped create the original Traffic Technology International distribution list 23 years ago, and has been working on it ever since. Outside of work, he is a keen fisherman, runs a drumming band, and plays an ancient version of cricket.