From 31 May 2023, an amendment to the Road Vehicles (Authorisation of Special Types) (General) Order 2003 (STGO) permanently authorised the use of Longer Semi-Trailers (LSTs) on roads in Great Britain. Because their overall length exceeds harmonised GB & EU limits, LSTs do not qualify for EC Whole Vehicle Type Approval. Nor do they fall within the GB domestic approval scheme. Instead, they are authorised solely under the STGO framework, and operators must comply with specific conditions.
- Route planning & risk assessments: operators must prepare written route plans, supported by a suitable risk assessment, and retain copies for inspection.
- Formal notifications: before an LST is first used, operators must notify the Secretary of State (via the VOL system if an O-licence is held).
- Construction requirements: trailers must have at least three axles (including at least one steered), comply with turning-circle standards, and be fitted with on-board weighing equipment if authorised to operate above 38t.
- Operational practice: driver training, safe loading procedures, accurate scheduling and proper record keeping remain essential expectations.
Operators that previously ran LSTs under the Government trial were required to transfer into the statutory STGO regime from 31 May 2023. All trial-based Vehicle Special Orders (VSOs) ceased to apply after 29 February 2024. For further details, see our full guide to Longer Semi-Trailers.
LST Quick Facts
- Status: Authorised in Great Britain under STGO since 31 May 2023
- Type Approval: Not type approved under EU or GB schemes – authorised only via STGO
- Length: Up to 15.65m trailer loading area / 18.55m overall combination
- Axles: Minimum of 3, with at least 1 steered
- Weight: Normal UK cap of 44t applies (no increase)
- Scope: Great Britain only – not valid for international operations
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