Navigating restricted roads is one of the most complex aspects of HGV driving in the UK. Weight restrictions, height restrictions, width restrictions, and time-based access restrictions create a patchwork of rules that vary by road, by vehicle type, and by time of day. Getting it wrong can result in prosecution, damage to infrastructure, and in the worst cases, serious accidents. This guide explains the main types of road restriction that affect HGV drivers and how to navigate them legally and safely.
Types of Road Restriction for HGVs
Road restrictions for HGVs fall into several categories, each with its own signing convention and legal basis:
| Restriction Type | Sign Description | Legal Basis |
|---|---|---|
| Weight restriction (GVW) | Red circle with weight in tonnes (e.g., "7.5T") | Road Traffic Regulation Act 1984 |
| Axle weight restriction | Red circle with weight and axle symbol | Road Traffic Regulation Act 1984 |
| Height restriction | Red and white striped rectangle with height (e.g., "4'6") | Road Traffic Regulation Act 1984 |
| Width restriction | Red circle with width measurement | Road Traffic Regulation Act 1984 |
| Length restriction | Red circle with length measurement | Road Traffic Regulation Act 1984 |
| Environmental weight restriction | Red circle with weight + "Except for access" | Local authority Traffic Regulation Order |
| Time-based restriction | Restriction sign with times/days panel | Traffic Regulation Order |
Weight Restrictions
Weight restrictions are the most common type of restriction affecting HGV drivers. They are imposed by local authorities under Traffic Regulation Orders (TROs) to protect roads and bridges from damage caused by heavy vehicles. A weight restriction sign showing "7.5T" means that vehicles with a gross vehicle weight (GVW) exceeding 7.5 tonnes are prohibited from using that road.
The key distinction is between GVW restrictions and axle weight restrictions. A GVW restriction applies to the total weight of the vehicle including load. An axle weight restriction applies to the weight carried on a single axle or axle group. A vehicle can be within its GVW limit but still exceed an axle weight restriction if the load is unevenly distributed.
Exemptions. Most weight restriction signs include an "Except for access" or "Except for loading" exemption. This means vehicles that need to access premises on the restricted road for loading, unloading, or delivery are exempt from the restriction. However, the exemption only applies to the specific premises being accessed — you cannot use a restricted road as a through route and claim an access exemption.
Bridge weight restrictions. Bridge weight restrictions are particularly important for HGV drivers. Bridges have a stated maximum weight capacity, and exceeding this can cause structural damage or collapse. Bridge weight restrictions are enforced by the bridge owner (National Highways, local authority, or Network Rail) and are displayed on signs at the approach to the bridge. If you are unsure whether your vehicle is within the bridge weight limit, do not proceed — find an alternative route.
Height Restrictions
Height restrictions are imposed to protect low bridges, overhead cables, and other structures. They are displayed on red and white striped rectangular signs showing the maximum permitted height. Unlike weight restrictions, height restrictions do not have an "Except for access" exemption — if your vehicle exceeds the stated height, you cannot legally proceed regardless of your destination.
Height restriction signs show the maximum height in both imperial (feet and inches) and metric (metres). The most common height restrictions are 4'6" (1.37m), 5'0" (1.52m), 6'0" (1.83m), and 14'6" (4.42m). The 14'6" restriction is common on railway bridges and represents the standard UK loading gauge.
Before entering a road with a height restriction, you must know your vehicle's laden height. The unladen height is shown on the cab sticker and in the vehicle handbook, but the laden height may be higher if the load extends above the cab. Always measure the actual laden height before entering a restricted road.
Width Restrictions
Width restrictions are less common than weight and height restrictions but are found on narrow rural roads, through villages, and at pinch points such as bridges and tunnels. They are displayed as a red circle with the maximum permitted width in metres or feet and inches.
Standard articulated lorries are 2.55 metres wide. Width restrictions of less than 2.6 metres will therefore affect most HGVs. Width restrictions of 3.0 metres or more will typically only affect abnormal loads and specialist wide vehicles.
Environmental Weight Restrictions
Environmental weight restrictions (EWRs) are a type of weight restriction imposed by local authorities to protect residential areas and rural roads from HGV traffic. Unlike standard weight restrictions, EWRs typically apply to all vehicles over a specified weight (commonly 7.5 tonnes or 18 tonnes) and are not limited to specific roads — they may apply to an entire zone or area.
EWRs are increasingly common in urban areas as local authorities seek to reduce HGV traffic on residential streets. The London Lorry Control Scheme (LLCS) is the largest example in the UK — it restricts HGVs over 18 tonnes from using certain roads in Greater London between 9pm and 7am on weekdays and all day on weekends, unless the operator holds a permit.
Operators whose vehicles regularly use restricted roads should check whether they need a permit under the relevant scheme. Operating without a required permit can result in prosecution and significant fines.
Time-Based Restrictions
Many road restrictions apply only at certain times of day or on certain days of the week. Time-based restrictions are indicated by a times/days panel below the main restriction sign. Common time-based restrictions include:
- Delivery restrictions in town centres (e.g., no HGV deliveries between 7am–10am and 4pm–7pm)
- School zone restrictions during school hours
- Night-time restrictions in residential areas
- Weekend restrictions in tourist areas
Time-based restrictions are enforced by local authority civil enforcement officers and DVSA enforcement officers. Fixed penalty notices can be issued for breaches, and persistent offenders may face prosecution.
Using a Truck Satnav to Navigate Restrictions
A truck-specific satnav is an essential tool for navigating restricted roads. Unlike standard car satnavs, truck satnavs allow you to enter your vehicle's weight, height, width, and length, and will route you around roads where your vehicle would be in breach of a restriction. Popular truck satnavs include the Garmin dēzl series, TomTom GO Expert, Sygic Truck, and CoPilot Truck.
However, truck satnavs are not infallible. They rely on map data that may not be fully up to date, and new restrictions may not be reflected immediately. Always observe physical road signs — if a sign contradicts your satnav, the sign takes precedence. Never drive past a restriction sign because your satnav says it is safe to do so.
Consequences of Breaching Road Restrictions
| Breach Type | Enforcement Body | Potential Penalty |
|---|---|---|
| Weight restriction breach | DVSA, police | Fixed penalty £100–£300; prosecution up to £5,000 |
| Height restriction breach (bridge strike) | Police, Network Rail | Prosecution; civil liability for repair costs |
| London Lorry Control Scheme breach | TfL | Fixed penalty £550 (reduced to £275 if paid within 14 days) |
| Environmental weight restriction breach | Local authority | Fixed penalty £100–£300 |
| Time-based restriction breach | Local authority, police | Fixed penalty £100 |
Operator Responsibilities
Operators have a legal duty to ensure that their vehicles are not driven on roads where they would breach a restriction. This includes providing drivers with appropriate route planning tools (truck satnavs, route cards), briefing drivers on known restrictions on their routes, and maintaining accurate records of vehicle dimensions and weights. Operators whose vehicles repeatedly breach restrictions may face action against their operator's licence.
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- HGV Overloading Penalties UK: Fines, Prohibition Notices and Prosecution
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