Abnormal Indivisible Loads - AIL

An Abnormal Indivisible Load (AIL) is any load that cannot be broken down into smaller loads for transport without undue expense or risk of damage, e.g. a 180-tonne transformer. Whereas an articulated vehicle carrying a normal load can reduce the weight of the load by removing part of it and redistributing the remainder, this is not the case of an AIL.

An AIL is also any load that exceeds certain parameters for weight, length, and width, whereupon the vehicle carrying the load would not comply with Construction and Use (C&U) Regulations due to the weight of the load exceeding 44,000 kgs; or as a result of the width and/or length of the load dictating that it can only be carried on a heavy motor car, trailer or combination of both where the same would not comply with the C&U Regulations in all respects.

AIL's are a complex subject due to the regulations that affect them. This section merely gives a brief insight into AIL's and their carriage.

Indivisible loads which are abnormal only in respect of their dimensions and not their weight may be able to be carried on standard vehicles subject to the C&U Regulations. However, it must be noted here that loads wider than 4.3 metres cannot be carried under C&U Regulations and all movements where a load wider than 4.3 metres is concerned must comply with Authorisation of Special Types General Order 2003 (STGO) rules.

Special Types Rules

The Special Types rules permit:

  • Abnormal Indivisible Loads (AIL's) to be carried which exceed the weight and/or dimensions limits contained in the Road Vehicles (Construction and Use) Regulations 1986, the Road Vehicles (Authorised Weight) Regulations 1998; and in cases where;
  • A variety of unusual vehicles, such as items of engineering plant or military vehicles, whose design and function prevents compliance with Construction and Use regulations, to be used on public roads in certain circumstances

These rules are contained in Section 44 of the Road Traffic Act 1988 and the Motor Vehicles (Authorisation of Special Types) General Order 2003 (STGO). Only AIL's may be carried under these rules. Information about Section 44 can be found on the Section 44 page within these topics.

Rules governing Weights and Dimensions are to be found in Section 41 of the Road Traffic Act 1988.

Vehicle Categories and Weights

Vehicles are classified into three groups according to total laden weight. Current categories are set out below with their related axle weights and spacings. A vehicle can be used in any category provided it meets all the conditions of that category. An empty vehicle can travel in a different category when unladen.

The maximum gross weights for the three categories are:

Vehicle categories and weights

In the table above, D is the distance (measured in metres) between:

  • The foremost axle and the rearmost axle of the vehicle carrying the load;
  • In the case of an articulated vehicle, the kingpin and the rearmost axle on the semi-trailer; or,
  • In the case of any other description of combination, the foremost axle and the rearmost axle of the group comprising all those vehicles in the combination that are carrying a load

Category 1 vehicles or combinations must have, at least, six axles. However, Category 1 articulated vehicles up to 46,000 kgs may have five axles.

Notifying the authorities

Depending on the load you’re moving and your route, you may need to give advance warning to:

  • The police
  • Highway authorities
  • Bridge and structure owners such as Network Rail

You can use Highways England’s electronic service delivery for abnormal loads (ESDAL) at the following link - https://www.gov.uk/esdal-abnormal-load-notification this will enable you to:

  • Plot your route
  • Notify the police, highways and bridge authorities of your abnormal load movements around the road network
  • Get advance notice of any possible route problems
  • Save vehicle details and routes for future use

If you do not use ESDAL you must fill in an abnormal loads movement application form which can be found in the Additional Abnormal Indivisible Loads Section

Give advance notice

You must allow time to get the necessary clearances from the police, highway and bridge authorities. For example, a Special Order application must be completed 10 weeks before the scheduled date of the move.

Read the fact sheet for notice requirements below:

Taking an Abnormal Load abroad

If you are taking an abnormal load outside the UK, you will need to:

  • Register your trailer
  • Get an Abnormal Load Trailer Keeper’s certificate

Links to register your trailer and obtain an Abnormal Load Trailer Keepers Certificate can be found below under downloads.

Check if a load is abnormal in another country

Some countries measure abnormal loads differently from the UK.

Check with each country you are travelling through to find out if the load you are transporting counts as abnormal - if it does, you will need to:

  • Get an Abnormal Load Trailer Keeper’s Certificate
  • Keep the certificate in your vehicle as you will need to show it at the border

Register your trailer to take abroad

Abnormal load trailer keeper’s certificate to be used abroad - DVSA 0248 Form