Low and weight-restricted bridges
There are some bridges in Northern Ireland which road users should exercise extreme caution when using. These include low bridges and weight-restricted bridges. They range from box culvert to large steel structures such as the Foyle Bridge. Interactive maps can help show where these bridges are located.
Low bridges - interactive map
Each year large vehicles collide with overhead bridges. Such collisions endanger lives, as well as cause delays on the road and rail networks.
A railway bridge collision could also result in the derailment of a train, with potentially disastrous consequences.
An interactive map has been produced to tell drivers of high vehicles, or vehicles with high loads, about bridges with less than 16 feet six inches (5.03 metres) clearance.
The interactive map at the following link shows low bridges that require road users to be extremely cautious when travelling under them and weight-restricted bridges:
List of low bridge locations
You can also find a list of low bridge locations at this link:
Weight-restricted bridges
To protect the road network (including bridges) and the safety of road users, weight restrictions will refer to maximum gross weight (MGW), rather than laden or unladen weight and is shown on the interactive map.
You can also find a list of weight-restricted bridge locations at this link:
Know your road signs
The signs below are used to show the maximum headroom of the hazard in both imperial and metric units.
Do not ignore them.
Advance warning of a low bridge
Some arch bridges may have a specific headroom over a specific width. This is designated by a white chord on the arch, as shown below.
Black and yellow bands may be added to the arches or girders and parapet walls to improve their visibility.
Special road markings may also be used to help guide high vehicles through the highest part of the arch.
Remember these three simple safety rules:
- know your height
- know your route
- know your signs
If you have a long load, remember to take care at bridges where the road curves or dips.
If you have a collision
If your vehicle does collide with a bridge, tell the PSNI immediately and advise the relevant authority.
If it is a railway bridge, Northern Ireland Railways must be informed immediately.
- phone: 028 9089 9400
Department for Infrastructure (DfI) Roads
Department for Infrastructure (DfI) Roads is the sole road authority in Northern Ireland, responsible for around 5,800 bridges.
If you need any further information, contact DfI Roads.