From 10 July 2011, newly approved types of heavy goods vehicles operating in the UK with a mass over 7.5 tonnes and trailers with a mass over 3.5 tonnes, were required by law to be fitted with retro-reflective vehicle safety markings.
With the exception of chassis-cabs, incomplete vehicles and tractors for semi-trailers; to the rear, full contour markings are required on all vehicles exceeding 2.1m in width. The reflective tape must mark the vertical and horizontal edges of the body and must be between 50-60mm wide and coloured either yellow or red. They must be fitted as close to the body edge as is possible or practical with the horizontal markings covering at least 80% of the body width (if this proves to be impossible then the coverage can be reduced to 60%). There must be at least 200mm distance between the rear markings and the stop lights.
To the side, there is a requirement for ‘partial contour’ markings for vehicles and trailers exceeding 6m in length (including the drawbar for trailers). It requires a single line of yellow or white reflective tape and must be applied as low as possible along the lower edge of the body, but no lower than 250mm above the ground or higher than 1.5m. This height requirement can be increased up to 2.1m above the ground where technical conditions prevent compliance with the 1.5m maximum height.
Note: vehicles fitted with full conspicuity markings do not require rear reflective markings.