Abstract
Enforcement officers check-weigh goods vehicles using slow speed ('dynamic') axle weighers. Each weigher consists of a weighbeam which is installed in a length of concrete (the 'apron') laid to a precision of + or - 3 mm and which measures the loads imposed by axles as they pass over it axle by axle at a speed of not more than 2.5 mile/h. Trrl has test-weighed goods vehicles on three axle weighers to determine how the precision of each apron's construction influenced the accuracy of weighing vehicles. This report describes the test results and their implications on the accuracy with which vehicles can be weighed. The verification procedure that is used to check a weigher's accuracy is discussed.