The figures are from random roadside stops of GB and non-GB trucks, trailers and buses for roadworthiness and traffic compliance issues.
Generally speaking, in the last few years, non-GB vehicles and trailers have more frequently attracted a penalty than GB ones. For example, the biggest disparity is between the defect rates (per check) of non-GB and GB trailers: in 2016-17, 15.4% for non-GB trailers compared to 12.5% for GB trailers, combining immediate and delayed fines, and inspection notices.
Also, the latest traffic offence rate of non-GB vehicles was 14.6% (combining serious offences and warnings) compared to 10% for GB vehicles.
Historical data of prohibition rates, also provided by DVSA, show that the compliance gap between foreign and GB vehicles has been decreasing for a few years; trailers for three years, and HGVs for two, thanks to better performance of foreign vehicles, and worsening performance of domestic ones.
This year, prohibition rates for foreign and domestic HGVs have nearly reached touching distance: 12.5% versus 11.0%, respectively, their closest approach so far. For vehicle and trailer defect rates, which also include inspection notices, non-GB vehicles actually fare slightly better than GB vehicles: 24% compared to 24.7%, although the margin of error is not given. This seems to follow an historical trend. Last year, the two were exactly the same: 25.1%, and the year before GB vehicles were ahead, 23.8% compared to 25.7%.
The data used in the report was provided by the Department for Transport’s in-house analytical consultancy.
UPDATED - 14/11/2017 12:50: Caption added to figure