Bridge of Don carries the A956 across the River Don in north Aberdeen. The bridge was originally completed in 1832, after a lengthy construction phase, and even longer design phase. Both John Rennie and Robert Stevenson submitted designs for a bridge in the early 1820s, but it was not until 1827 that a design by Thomas Telford was accepted. Unfortunately, there were problems with subsidence during construction, and piers and arches had to be taken down for additional piling to be carried out. Eventually, however, this was remedied and the bridge was completed in 1832.
The bridge as first built consisted of 5 granite arches spanning the river, with rounded cut waters rising up the piers to form refuges, which are now home to lamp posts. At 26ft in width, the bridge was able to carry two-way traffic and pavements, but by the 1950s traffic levels required more than this. As a result, the bridge was widened. However, instead of simply mating a new concrete structure to the face, a whole new bridge was built alongside, with the concrete deck cantilevered out to meet the old bridge. From the road, there is no obvious join, but go down to the river bank and it is possible to see daylight between the old and new piers. Furthermore, unlike most bridge widenings, the profile of the arches has not been matched, and the new bridge has thinner piers, with slightly wider arches.