Weight limit and ‘Unsuitable for HGVs’ signs
There are some circumstances in which weight restrictions need to be imposed on the movement of heavy goods vehicles (HGVs).
Weight restrictions fall into two categories – environmental and structural.
Environmental weight restrictions
A restriction can be imposed for environmental reasons on routes which have been identified as unsuitable for use by HGVs, and where there is a better and equally convenient alternative. An environmental weight restriction will usually only apply to vehicles with a maximum gross weight of 7.5 tonnes or above. The maximum gross weight is the maximum permitted weight of the vehicle when fully loaded.
Environmental restrictions can be applied to individual routes or a defined area of roads that have been determined as unsuitable for use by vehicles over a certain width or weight. They are useful in preventing heavy goods vehicles from using minor roads as inappropriate short-cuts between main routes. Reasons we may introduce a restriction of this nature include:
- Preventing damage to the road infrastructure (carriageway, footway, street furniture) and buildings.
- Protecting the character and environment of rural areas, villages and residential estates.
- Managing congestion on our roads.
- Reducing risks to vulnerable road users, including pedestrians and cyclists.
When proposing a weight restriction for any route or area, we must give careful consideration to those vehicles that will be re-routed. In some cases, a route may seem inappropriate for HGV use but there may be no other realistic alternative. If there are no alternative routes, introducing a weight restriction will only move probelms onto other inappropriate roads. Where alternative routes are available we give early warning of a weight restricted area and show the alternative route.
Exemptions to environmental weight restrictions
- Vehicles making deliveries or collections at premises within the restriction.
- Vehicles working on or near the roads in question.
- Emergency service and military vehicles.
- Buses, coaches and other public service vehicles.
This means that vehicles requiring legitimate access within the area covered by the weight limit, such as to deliver to a shop, access a farm or an industrial unit are permitted.
Structural weight restrictions
A weight restriction of less than 7.5 tonnes can only be imposed on a route for structural reasons. A structural weight restriction will only be used on routes that have weak structures, such as bridges, that cannot bear vehicles over a certain weight (e.g. three tonnes) and can only safely accommodate a lower load. Restrictions of this type will typically cover only short sections, where the structure is located.
A structural restriction will not normally include an exemption for access as the structure may fail should it be overloaded.
All major highway bridges in the Scottish Borders have been assessed to check that they are capable of carrying full road loading. Bridges that failed this assessment are strengthened to meet the latest requirements if a weight limit is not already in place.
As well as formal restrictions, potential alternative solutions include advisory signing and working with the satellite navigation (satnav) companies.
This type of signing consists generally of ‘white on blue’ signs with legends such as ‘Unsuitable for Heavy Goods Vehicles’ or with a pictorial representation of an HGV showing a red slash through the vehicle symbol and are to indicate that a road may be generally unsuitable for an HGV.
‘Unsuitable’ may be due to:
- limited width due to sharp bend or walls either side of the road
- steep gradients such that a long or articulated vehicle may struggle to negotiate the hazard
The signing is advisory and there is no recourse to the law if an HGV tries to negotiate the road.
Some ‘unsuitable’ roads are in conservation areas and requests for advisory signing will be treated on an individual basis in those circumstances.
To request consideration for signs and/or weight restrictions, contact the Road Safety team.
Satellite Navigation Systems
The use of satnav devices brings up a number of issues when used by HGV drivers.
- HGV versions of satnav devices are available that have built into their mapping roads that are not suitable for an HGV, but there is no guarantee that every HGV driver is supplied with this technology. HGVs cannot negotiate some small streets or tight bends that their satnav might try to direct them along.
- Many satnavs are supplied with a map which is correct at the time of purchase but may not be updated if roads or their attributes change. We have contact details for the major satnav mapping companies, and regularly supply information to them on changes and additions to the road network, including roads that are, or become, unsuitable for HGVs. These companies incorporate changes to their mapping.
To request that we contact satnav mapping companies to update a road as unsuitable for HGVs, contact the Road Safety team with details of the route in question.