HGV Abnormal Load Rules UK 2026: Complete Guide
Abnormal loads — vehicles or combinations that exceed standard legal dimensions or weight limits — require special authorisation, careful route planning, and in some cases police escorts. This guide explains the rules governing abnormal loads in the UK, the notification requirements, and the responsibilities of operators and drivers.
What Is an Abnormal Load?
An abnormal load (also called an abnormal indivisible load, or AIL) is a load that cannot be divided into smaller pieces without disproportionate cost or risk, and which exceeds one or more of the standard legal limits for road vehicles in the UK.
The standard legal limits for HGVs are:
| Parameter | Standard Legal Limit |
|---|---|
| Maximum gross weight | 44 tonnes (for 5-axle artic) |
| Maximum width | 2.55 metres (2.6 metres for refrigerated vehicles) |
| Maximum height | No national limit, but 4.65 metres is the practical standard |
| Maximum length (artic) | 16.5 metres |
| Maximum length (rigid) | 12 metres |
Any vehicle or combination that exceeds these limits requires special authorisation under the Road Vehicles (Authorisation of Special Types) General Order 2003 (STGO) or a Special Types General Order (STGO) category.
STGO Categories
The STGO divides abnormal loads into three categories based on gross weight:
| Category | Gross Weight Range | Maximum Speed | Notification Required |
|---|---|---|---|
| STGO Cat 1 | 44–80 tonnes | 40 mph motorway / 30 mph other roads | 2 days' notice to police and highway authorities |
| STGO Cat 2 | 80–150 tonnes | 40 mph motorway / 25 mph other roads | 5 days' notice to police and highway authorities |
| STGO Cat 3 | 150+ tonnes | 12 mph | 5 days' notice plus police escort required |
Loads that exceed width or length limits but remain within standard weight limits fall under separate provisions and may require different notification periods.
Who Must Be Notified?
The notification requirements for abnormal loads depend on the category and the route. In general, you must notify:
The police — The chief officer of police for each police area the load will pass through. Notification must be given at least two days before the movement (five days for Cat 2 and Cat 3). The police may impose conditions on the movement, including time restrictions, route modifications, and escort requirements.
Highway authorities — The relevant highway authority (typically the local council or National Highways for motorways and major A-roads) for each road the load will use. They may require bridge assessments, impose weight restrictions, or require temporary traffic management.
Utility companies — If the load is very wide or tall, you may need to notify utility companies so that overhead cables can be raised or traffic lights temporarily removed.
Notifications are typically submitted through the ESDAL (Electronic Service Delivery for Abnormal Loads) system, which is the government's online platform for managing abnormal load movements in England. Scotland, Wales, and Northern Ireland have their own notification systems.
Route Planning for Abnormal Loads
Route planning is one of the most critical aspects of abnormal load operations. The route must be assessed for:
Bridge strength — Every bridge on the route must be capable of bearing the load. Bridge weight limits are posted on signs, but the operator is responsible for checking with the relevant highway authority that the bridge can carry the specific axle configuration and gross weight of the movement.
Overhead obstructions — Power lines, railway bridges, and other overhead structures must be checked against the height of the load. The minimum clearance under Network Rail bridges is typically 5.03 metres, but many older structures are lower.
Road width — Very wide loads may not be able to navigate tight bends, roundabouts, or narrow lanes. The route must be driven in advance (or assessed using mapping tools) to identify any restrictions.
Traffic management — Some movements require temporary traffic signals, road closures, or police escorts to manage the impact on other road users.
Escort Vehicles
Escort vehicles (also called attendant vehicles) are required for loads that exceed certain dimensions:
| Condition | Escort Requirement |
|---|---|
| Width over 3.5 metres | One attendant vehicle (front or rear) |
| Width over 4.3 metres | Two attendant vehicles (front and rear) |
| Width over 6.1 metres | Police escort required |
| STGO Cat 3 (150+ tonnes) | Police escort always required |
| Length over 25.9 metres | One attendant vehicle |
Escort vehicle drivers must hold a valid driving licence and must be trained in abnormal load escort procedures. The escort vehicle must be equipped with an amber beacon, a "WIDE LOAD" or "LONG LOAD" sign, and a two-way radio for communication with the load vehicle.
Speed Limits for Abnormal Loads
Abnormal loads are subject to lower speed limits than standard HGVs. The limits depend on the STGO category and the type of road:
- STGO Cat 1: 40 mph on motorways, 30 mph on other roads
- STGO Cat 2: 40 mph on motorways, 25 mph on other roads
- STGO Cat 3: 12 mph on all roads
These limits are absolute — there is no provision for exceeding them even briefly. DVSA enforcement officers and police can stop and prohibit an abnormal load movement if the speed limits are being exceeded.
Time Restrictions
Many abnormal load movements are restricted to certain times of day to minimise disruption to other road users. Common restrictions include:
- No movement during peak hours (typically 7–9am and 4–7pm on weekdays)
- No movement on bank holidays or during major events
- Night-only movements for very wide or long loads in urban areas
Time restrictions are imposed by the police and highway authorities as conditions of the notification. Failure to comply with these conditions is a criminal offence.
Driver Requirements
There are no specific additional licence requirements for driving abnormal load vehicles beyond the standard Category C or C+E licence. However, operators are expected to ensure that drivers are adequately trained and experienced in abnormal load operations. This includes:
- Understanding the notification and route planning requirements
- Knowledge of the STGO conditions that apply to the movement
- Ability to communicate effectively with escort vehicle drivers and police
- Awareness of the specific handling characteristics of the vehicle and load
Penalties for Non-Compliance
Operating an abnormal load without the required notification or in breach of STGO conditions is a criminal offence. Penalties include:
- Fixed penalty notices
- Prohibition of the vehicle until the load is made legal or the movement is properly authorised
- Prosecution, with fines of up to £5,000 per offence
- In serious cases, endorsement of the operator's licence
Bridge strikes caused by abnormal loads that have not been properly assessed can result in prosecution for criminal damage, with potentially unlimited fines and imprisonment.
Summary
Abnormal load operations require careful planning, proper notification, and strict compliance with STGO conditions. The notification requirements vary by load category — from two days for Cat 1 loads to five days plus a police escort for Cat 3 loads. Route planning must address bridge strength, overhead obstructions, and road width. Escort vehicles are required for loads over 3.5 metres wide, and police escorts are mandatory for loads over 6.1 metres wide or in the Cat 3 weight category. Non-compliance carries significant penalties and can put your operator licence at risk.
