Weight limits

Weight restrictions can be imposed for structural or for environmental reasons. It is a legal control imposed on vehicles above a specified weight or width, on specific roads and routes.
The restriction prevents lorries from using inappropriate roads, routes and areas in order to:

  • Reduce danger to pedestrians and other road users  
  • Prevent damage to buildings, roads and bridges  
  • Preserve the character, amenity and environment of an area  
  • Reduce and manage congestion on the roads       

Procedures for Implementation 

  • Restrictions are subject to a Traffic Regulation Order (TRO) and the associated procedures.  
  • Regulatory signs are erected on site to give effect to the TRO and to assist the police in carrying out its enforcement but they need to be backed up by widespread advisory signing giving early warnings to lorry drivers that a particular route or area is restricted.     


This is a matter for the police but they have limited resources to enforce this type of restriction.  Weight limits made on structural grounds usually apply to very short lengths of road and usually contain no exemptions.  Weight limits made on environmental grounds however usually apply to much longer lengths of road or areas surrounded by appropriate lorry routes.  Lorries still need to gain access to local shops, businesses and residential properties located within restricted lengths of roads and Traffic Regulation Orders therefore contain "except for access" or "except for loading" clauses which make them difficult to enforce.  For this reason enforcement commands a low priority and where possible, restrictions should be well signed to ensure that they are 'self enforcing' or, if necessary, physical measures introduced to prevent abuse.  Restrictions will only be introduced if there is a suitable alternative route for the displaced traffic and the displaced traffic does not create a problem elsewhere. 

Additional Considerations

Where a Traffic Regulation Order restricts the use of a road, route or area to certain vehicles, drivers will need to be directed by signing to an alternative route.