Prioritising bridge maintenance

Transport Scotland is responsible for the management and maintenance of trunk road bridges and structures in Scotland and public safety and availability of the network are paramount.

Transport Scotland places great importance on the design and implementation of appropriate cost effective maintenance and strengthening solutions, to ensure bridge safety and minimise disruption to road users and to the environment.

Bridges and structures that are part of the road asset are, like trunk roads, managed and maintained by Operating Companies who are contracted by Transport Scotland on behalf of the Scottish Government. They carry out day-to-day inspection, management, maintenance and repairs to trunk road bridges and structures 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 and the M77 from Junction 5 to Fenwick.

The current bridges inventory consists of some 1900 bridges and footbridges and over 3700 culverts, gantries, high mast lighting and retaining walls.

Some major bridges on the trunk road network are: A898 Erskine Bridge, A9 Kessock Bridge, M8 Whitecart Bridge, A87 Skye Bridge, M90 Friarton Bridge, A876 Kincardine Bridge, A876 Connel Bridge, M8 Kingston Bridge, A82 Ballahullish Bridge.

Along with a major project to construct a new Forth Crossing there are plans for smaller scale bridge projects to strengthen or replace existing bridges, see Bridge Projects. The Forth Replacement Crossing is a major infrastructure project for Scotland designed to safeguard a vital connection in the transport network.

The gross asset value of the bridges stock is £4.39 billion.

The biggest challenges are an aging bridge stock, corrosion and new and higher standards.

Work on bridges is brigaded under three main headings: Asset Management and Maintenance, Overseeing Organisation Duties and New Trunk Road Structures.

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.

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. The bridge assessment programme is now complete and a strengthening programme is underway and due for completion 2010-12 allowing 40-44 tonne HGVs to use all trunk road bridges without restriction or monitoring. It also provides advice and guidance on the technical aspects of abnormal load routing and safe movement of high loads.

Overseeing Organisation Duties

Transport Scotland is the technical approval authority for trunk road structures in Scotland and responsible for the determination of departures from standards associated with structures.

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