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Prioritising bridge maintenance

Transport Scotland maintains and operates trunk road bridges and structures across Scotland.

Our responsibilities 

Transport Scotland is responsible for the management, maintenance and operation of trunk road bridges and structures in Scotland. 

Our aim is to ensure bridge safety and minimise delay and disruption to the public, road users and the environment.

A87 Skye BridgeBridges and structures that are part of the road asset are managed and maintained by Operating Companies contracted by Transport Scotland on behalf of the Scottish Government. They carry out inspections, monitoring, management, maintenance and repairs to trunk road bridges and structures.

This is in accordance with the term maintenance contracts and the Design, Build, Finance and Operate (DBFO) contracts for the A74(M) from Junction 12 to the English Border, the M77 from Junction 5 to Fenwick and the M80 from Stepps to Haggs.

We maintain 4714 structures including 1933 bridges and more than 2781 culverts, gantries, high mast lighting and retaining walls.

The gross asset value of the bridges stock is £5.5bn.

Our bridges are also key to Scotland's culture and heritage, with 49 bridges of Historic Interest and six of National Importance, designated as Scheduled Ancient Monuments.

Nine major bridges on the trunk road network have main spans greater than 100m, with structural forms including:

  • steel box girders
  • cable stay
  • steel girder truss and
  • steel and concrete post tensioned box girders.

Transport Scotland is currently working on a major project to deliver the Queensferry Crossing on the Forth. This work is on track for completion in 2016.

Read more about the Forth Replacement Crossing project.

Artist's impression of the new Queensferry Crossing

Other estuarial or river crossings include:

  • A898 Erskine Bridge
  • A9 Kessock Bridge
  • A9 Cromarty Bridge
  • A9 Dornoch Bridge
  • M8 Kingston Bridge
  • M8 Whitecart Viaduct
  • A87 Skye Bridge
  • M90 Friarton Bridge
  • A985 Kincardine Bridge
  • A878 Clackmananshire Bridge
  • A876 Connel Bridge  
  • A82 Ballachulish Bridge

Transport Scotland also operates six canal swing bridges in co-operation with Scottish Canals on the Caledonian and Crinan Canals.

Asset management and maintenance

Asset management best practice is being developed in line with the new Code of Practice for the Management of Highway Structures.

To assist its management and overseeing role a database, Structures Management System (SMS), containing an inventory of all trunk road bridges and structures is used by Transport Scotland and its Operating Companies.

A82 Ba Bridge, Rannoch Moor

Transport Scotland is responsible for management and maintenance technical policy as well as overseeing operational management, the annual maintenance programme and the annual bridge inspection programme, where some 700 principal and 1400 general inspections are carried out per annum.

Since 2000, 40-44 tonne HGVs have been permitted to use public roads and in advance of the 1990s and continuing beyond 2000, a prioritised bridge assessment programme was undertaken to ensure the bridges could carry these heavier loads. This is now complete.

Since the late 1990s, a bridge strengthening and replacement programme has been ongoing and due for completion by 2020, allowing 40-44 tonne HGVs to continue to use all trunk road bridges without weight or traffic restrictions. Where bridges are yet to be strengthened or replaced they are subject to a monitoring regime to ensure they remain safe to use.

Transport Scotland provides advice and guidance on the technical aspects of abnormal load routing and safe movement of high loads.

Overseeing organisation

Transport Scotland is the technical approval authority for trunk road structures in Scotland, for all structures and bridges that support or cross it and is responsible for the determination of departures from design, construction and maintenance standards associated with structures.

As the national bridge authority for Scotland it also has membership of the UK Bridges Board, the Bridge Owners’ Forum and the SCOTS Bridges Group.

As one of the four national UK Overseeing Organisations it provides advice on bridge and structural matters in Scotland to local authorities where its close working relationship with the Highways Agency in England is invaluable.

It also provides advice to other parts of Transport Scotland, and the Scottish Government as well as liaison with third parties such as Network Rail, consultants and contractors.

New Trunk Road structures

The Bridges Section at Transport Scotland provides support and advice to Major Transport Infrastructure Projects Directorate (MTRIPS) on all bridge and structural aspects associated with new trunk road schemes involving the development of options, employer’s requirements, review of outline and tender proposals and input into aesthetic aspects of bridge and structural form where it is assisted by Transport Scotland’s Architectural Adviser.

It also provides advice and guidance to Transport Scotland rail teams and on developer bridge schemes.

Abnormal load routing

Transport Scotland co-ordinates the movement of abnormal loads throughout Scotland’s trunk and non-trunk road network, ensuring that the requirements of industry are met, while minimising the risk to road safety and delays to other road users, and also safeguarding bridges from damage by overweight or over height vehicles.

The primary function of Transport Scotland’s Abnormal Routing Section is to investigate on behalf of the Highways Agency, the suitability of proposed wide, high and heavy load movements within Scotland that require VR1 or Special Order authorisation under Section 44 of the Road Traffic Act.

Before recommending to the Highways Agency that any such authorisation is given, Abnormal Routing Section must be satisfied that the movement can be justified, and that alternatives have been considered – consulting with its Operating Companies, Local Authorities, other Bridge Owners and the Police where necessary along the route of the proposed movement.

From the records held, and the experience gained in performing these duties, it is also able to offer a routing advisory service on the movement of all abnormal loads, and high loads, throughout Scotland.

This service is highly regarded by haulage contractors, plant operators and the manufacturing & construction industry throughout the UK – assisting them with their day-to-day transport problems and enabling them to fully investigate all options prior to tendering for transportation of wide, high or heavy loads.

The Abnormal Routing Section can also advise haulage contractors and plant operators of the road authorities whose area they propose to travel through – thereby reducing the likelihood of an authority not being notified of the proposed movement

View the document: Abnormal load movements - a brief guide to notification and authorisation requirements

Further details on abnormal loads can also be obtained on the Highways Agency’s Electronic Service Delivery for Abnormal Loads (ESDAL) website.

For more information on this area please contact: 

Trunk Road and Bus Operations Directorate: Network Administration (Abnormal Load Routing)
Buchanan House
58 Port Dundas Road
G4 0HF

Telephone: 0141 272 7339


High loads

Strike it out, preventing bridge strikesThere is currently no legislation which limits the height of vehicles that can travel on the roads in the UK. Drivers are not required to notify or seek approval to travel because of vehicle height.

Until the implementation of our Overheight Vehicle Strategy in 2008, records showed an increase in bridge strike incidents on Scotland's Trunk Road Network involving over-height vehicles. The consequences are always costly.

They can be fatal for both the driver of the vehicle and the people on or under the bridge in passing rail or road traffic.

Transport Scotland's 'Strike It Out' campaign is aimed at raising awareness of bridge strikes on the Scottish road network, proactively stressing the safety risks associated with overheight vehicles and calling for drivers to plan their journeys ahead using a freephone helpline and web page.

View our campaign leaflet and our Strike It Out blog.

The standard minimum clearance on every part of a public highway is 16'-6" (5.03m). All bridges with lower clearances have signs identifying the maximum safe vehicle height which can pass beneath.

High vehicles are those which:

  • cannot pass safely under a bridge of 16'-6" (5.03m) minimum headroom; or
  • have a vehicle/load combination greater than 16'-3" (4.95m) high - allowing for the minimum safety margin of 0.275m.

Legislation states that all vehicles 9'-10" (3.0m) and above require a notice in the cab displaying the maximum height of the vehicle. It is an offence not to display this notice.

It is the responsibility of the driver of a vehicle to ensure that the height of their vehicle, including the load, can safely pass beneath all overbridges encountered on a route.

Further guidance to increase awareness and offer advice regarding high loads and bridge strikes is available on the DfT website

Further information on bridge heights within Scotland can be found on the Freight Scotland website, and in the Notification to Hauliers document.

Transport Scotland has also produced a series of Freight Best Practice guides and case studies that can help save fuel, reduce emissions and increase safety. 

The High Load Grid is a collection of advisory routes for extremely high loads. This is aimed at assisting the haulage industry plan moves and ensuring routes are maintained to agreed capacities. The high load routes are either 18' or 20'. The High Load Grid can be used as a guide to locate routes in a required area. First published in 1996 it has been periodically updated to reflect changes in the local and trunk road network. It has been temporarily withdrawn for review and updating and will be available again in Spring 2017. In the interim should you require any assistance planning a high load and/or abnormal load movement and require more information in this area please contact

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