the accuracy of weigh-in-motion data is generally much less than for static weigh scales where the environment is better controlled. the european cost 323 group developed an accuracy classification framework in the 1990's. they also coordinated three independently controlled road tests of commercially available and prototype wim systems, one in switzerland, one in france (continental motorway test) and one in northern sweden (cold environment test). better accuracy can be achieved with multiple-sensor wim systems and careful compensation for the effects of temperature. the federal highway administration in the united states have published quality assurance criteria for wim systems whose data is included in the long term pavement performance project.