During the late 1980s and the 1990s the council undertook a programme to assess the load carrying capacity of its highway bridges which have a span of 1.5m or more. These assessments were carried out to BD21, The Assessment of Highway Structures published by Her Majesty’s Stationery Office. They were a result of proposals to increase the weight of vehicles permitted to use the unrestricted highway from 38 to 40 tonnes.
The assessment process revealed several bridges to be weak. As a result, a bridge strengthening programme was instigated to ensure a viable road network county wide. The programme has strengthened over 40 bridges since 2000. Estimates suggest that the programme will need to continue until 2012 in order to address the remaining weak bridges.
In addition to bridge strengthening schemes, major maintenance work is undertaken to replace or repair structures which fall outside the scope of the bridge assessment programme.
The council’s capital budget funds the bridge strengthening programme and other major maintenance work.