Weigh in Motion and number plate recognition technology to help protect important Mearns bridge from damage

Weigh in Motion and number plate recognition technology to help protect important Mearns bridge from damage

Work started this week to install monitoring equipment on a Mearns road bridge as part of efforts to protect it from the impact of heavy vehicles using it in contravention of weight limits.

Inverbervie’s Jubilee Bridge, which carries the A92 Stonehaven-Dundee road and is the main entrance to the town, has already had temporary barriers installed to protect the parapet.

Now “Weigh in Motion” technology, supplemented by number plate recognition cameras, is being installed to further protect the bridge structure by identifying vehicles crossing it in excess of the 44 tonne standard road weight limit.

The system will remain in place for up to four years and will allow council bridges engineers to get better information on the structural damage inflicted on the crossing by unplanned use by vehicles carrying loads in excess of that permitted, to help safeguard its long-term integrity.

Installation work began yesterday (Monday, Nov 5) and should be complete by the end of the week. During this time, the following daytime traffic restrictions will be in place:

• Bridgeview side road will be closed
• The A92 will be reduced to a single carriageway with traffic lights in operation

Aberdeenshire Council’s Structures Manager, Donald MacPherson, said: “I think the public are starting to become more aware of the importance of our bridges to the local transportation network, particularly where they have been inconvenienced by closures linked to vehicular damage.

“Given recent publicity around damage to some of our historic bridges, including Gairnshiel, Spittal Burn and Abbeyton Bridges, this technology clearly may have the potential to be used in other locations, to identify vehicles contravening weight limits and causing damage.”

Chairman of Aberdeenshire Council’s Infrastructure Services Committee, Peter Argyle, said: “Doing this work now is intended to safeguard the bridge’s long term integrity, ultimately keeping this bridge and the road open for everybody, avoiding potentially lengthy closures and restrictions for repairs, so it’s great to see it begin and I look forward to seeing the impact of this technology.”

The work is being carried out at a cost of just over £150,000 and council engineers will be speaking to local residents who may be directly affected by the installation works.

Jubilee Bridge is an eight-span, reinforced concrete bridge which opened in 1935, it is 1,700 feet long and on a curve over the Bervie Water. It is known as the Jubilee Bridge because the opening coincided with the Silver Jubilee of King George the Fifth’s reign.

It took three years to build, during which time, in April 1934, a major spate on the river carried much of the props and scaffolding out to sea.

The bridge was refurbished in a major project nine years ago, to tackle corrosion, repair concrete and improve waterproofing on the bridge deck.

* In the UK, with some exceptions, the maximum vehicle weight is 44 tonnes gross (truck, fuel and load) and has up to 6 sets of axles. Engineers want to determine when and how often illegally overweight vehicles are using the bridge, using the new system.
See https://www.gov.uk/guidance/moving-goods-by-road