The Department is responsible for the enforcement of road traffic legislation. Records are kept of the number of operator licences issued. An operator licence may list a number of vehicles. The Department's records do not detail the number of vehicles as a percentage of the total heavy goods vehicles and public service vehicles fleets in use.
Although DVLA may have records of HGVs and PSVs registered, some will not require an operator licence. One operator licence holder can have multiple vehicles listed. In addition, it is not mandatory for PSV operators to list all the vehicles that they may use on their operator licence. So the DVLA and VOSA records cannot be directly compared.