Because agricultural vehicles are nor registered and licenced , their share in the vehicle fleet in the Netherlands is not precisely known. Depending on the source that is used, estimates range between 1% and 4% of the total fleet. Estimates by CUMELA[i] [1] result in 220,000 vehicles (200,000 tractors and 20,000 self-propelled machinery/motor vehicles with limited speed). The Dutch Safety Board [2] estimate is 97,000 vehicles (85,000 and 12,000 respectively). A more recent estimate by the Netherlands Vehicle Authority RDW [3] results in 400,000 vehicles (270,000 tractors and 130,000 motor vehicles with limited speed).
The number of kilometres travelled by agricultural vehicles on public roads is also unknown. In its mobility surveys OVG/MON/OViN[ii] , Statistics Netherlands does not include information about the traffic performance of agricultural vehicles or about the number of vehicles. It is known, however, that the continued scale increase in agriculture [4] [5] leads to farms with more agricultural lots scattered over a larger area, causing 'internal' agricultural traffic to use the public road more than they did earlier [5].