Regulations & governing bodies
The strategic road network in England (motorways and some A roads) is governed by Highways England, with other roads are managed by local authorities, country-specific government agencies (Transport Scotland or the Welsh Assembly), or by Transport for London.
In the US, roads & highways are governed at the state level, with the exception of The National Network (NN). Also known as the National Trucking Network, the NN is a network of state highways and interstates designated for use by large trucks. The NN includes almost all of the Interstate Highway System and other, specified non-Interstate highways.
Any CMV driver in the US can use any road in the NN and all states must give CMV drivers ‘reasonable access’ to the NN. Federal width & length limits apply on the NN, overriding any state limits.
The NN is recommended for through traffic – CMVs are only allowed to operate on other (truck-restricted) roads if they have no other way to access their destination.
In the UK, speed limits are set according to national standards – they may vary from road to road (built-up areas have different speed limits to motorways) and from vehicle to vehicle (cars have different speed limits to vans, buses or HGVs), but don’t typically vary overall throughout the UK (though local councils are able to set their own speed limits in certain areas, the national speed limits remain the same).
The speed limit (both general and for CMVs) varies state-to-state and by CMV type (trucks/buses) (See pg. 12-14 of this document for information or this list). These varying limits do apply on the National Network – so CMVs crossing state lines on the NN may have to be wary of their maximum speed.
Size and weight limits for commercial vehicles in Britain are set by the Department for Transport and do not vary regionally.
In the US, For CMVs travelling on the National Network, the FMCSA sets the federal the length, width, and weight limits. Provided the truck remains on the NN, they are not subject to the state limits, however, when they leave the NN they must either be within the state limits for whichever state they are travelling through at the time or carry specialised permits for vehicles & loads over the state limit. More information about length, width & height limits by state here.
There is no federal limit for truck height, though states may set their own limits, which do vary across the country usually 13’6” (on the east coast) and 14’ (on the west coast), with a few exceptions up to 15’.