The local authority is responsible for 3,500 miles of public road, carried by 1,308 bridges, which equates to a bridge approximately every 2.7 miles of road.
Nearly 70% of those bridges are more than 100 years old and with such an ageing bridge stock there is now a significant programme of works required to be carried out over the next 10 years.
In addition, a greater frequency of severe weather events has increased the number of bridge closures and restrictions due to flood damage.
The optimum investment necessary to maintain, repair and renew bridges over the next 20 years is projected to be £102 million – or around £5.1 million per year.
Aberdeenshire Council’s Infrastructure Services Committee approved the policy and procedure which sets out how required works will now be prioritised across the region and direct funding to where it does the most good.
Elected members heard that feedback from the council’s six area committees and a digital community engagement process were broadly similar.
Area committees were generally supportive of the approach, but had some concerns over the suitability of diversionary routes, the council’s operational ability to deliver the works and the importance of regular maintenance inspections.
The public engagement also raised additional concerns over the impact on communities of multiple closures, the financial impact on businesses and the re-routing of emergency services.
Philip McKay, Head of Service for Roads, Landscape Services and Waste Management with responsibility for Bridges, told committee: “We have listened carefully and we have taken into account the comments from both these exercises around the proposed prioritisation scheme. As a result we have made a number of changes to the policy, most notably around the bridge alert status. We now have a revised score which places a heavier weight on a bridge closure and brings it into line with the rating we would give for an imminent bridge closure.”
Network criticality and bridge alert status remain the principal elements in the scoring, however the engagement process raised concerns regarding the manner in which diversions are taken into account.
An additional resilience factor has now been included. It will be used in circumstances where there are already excessive bridge restrictions locally and there is a high risk of any further bridge or road incident in the local area restricting traffic movement to an unacceptable level.
Cllr Peter Argyle, chair of the Infrastructure Services Committee, said: “We fully recognise the difficulties and inconvenience caused to communities when bridges close either permanently or temporarily. The forthcoming introduction of our Infrastructure Fund will generate considerable additional capital to help tackle the backlog and future demands of our bridges
“We continue to face significant challenges with regards to the volume and age of our bridges. We have a lot of very old bridges which were never designed to take 21st century traffic. We also have the added challenge of climate change and more extreme weather conditions which have had a major detrimental impact on our bridges. And all the while we are being impacted by the continuing reduction of funding coming to Aberdeenshire Council and therefore the money we’ve been able to spend on our bridges.”