While highways and bridge authorities have had the opportunity to mark bridges with imperial and metric measurements in the past, this has been done by the installation of a separate sign. The proposed change gives the power to mark both measurements on one sign.
The DfT added that a lack of understanding of imperial measurements has been implicated in incidents of bridges struck by over height vehicles.
The Freight Transport Association (FTA) welcomed the news, saying it believes it is vital that signage can be easily understood by drivers who have to negotiate low bridges and narrow spaces.
Vehicles with an overall travelling height over three metres must have a notice in the cab which indicates the height in feet and inches or in imperial and metric.
Malcolm Bingham, FTA’s head of road network policy, said: “While the new rules have still to be finalised, it is proposed that highway authorities will be allowed to replace the current signs as they become life expired. FTA has urged the DfT to encourage early take-up of the new option.”