The first part of the Exeter Canal was completed in 1567, making it one of the first inland waterways to be built in England. It was originally built to bypass a weir which had been constructed across the Exe by the Countess of Devon in the late 1200s. This had the effect of cutting off Exeter's link to the sea and thus boosting the Countess's port at Topsham at the head of the estuary. The weir gave its name to the settlement which grew up there, Countess Wear.

Countess Wear bridge was built in the late 18th century as part of the road improvements carried out by the Turnpike Trusts, replacing a ford on the same site. Thomas Parker of Topsham was engaged to build the Countess Wear bridge to a conventional stone design. Work started in March 1771 and it was opened on 14 September 1774. It had seven spans of between 7 m. (23ft.) and 8m. (26ft.) in length. The width was 4m. (13ft 7in). In 1842, the two central arches were replaced by an 18 m.(60ft. arch). In 1938 the road was widened to 14 m. (45ft.) to cater for increased motor traffic along the new Exeter bypass.

A hundred and fifty metres from the Countess Wear Bridge,  parallel swing and bascule bridges take the A379 across the Exeter Canal. They are operated from a control room that looks similar to a bridge on a ship. They are designed to be opened to allow shipping to pass up and down the canal. Rarely raised nor swung now, because no commercial shipping uses the canal and tall yachts cannot pass under the M5 road bridge a little down stream. The bridges may not often open for water bourne traffic, but they are kept busy with 36,000 vehicles a day passing over them along the A379.

The canal has had a series of swing bridges prior to this one, including two by James Green, the County Surveyor in 1821 and 1831. The swing bridge dates from 1936, replacing an 8ft (2.5 metre) wide bridge, and is an early example of a steel plate riveted girder bridge. It was constructed as part of the £230,000 scheme to build the 5 mile long Exeter by-pass from Pinhoe to Peamore. The earlier bridge had very steep approaches on each side, and was not able to carry a large load. The new bridge was tested with 10 heavy steam rollers weighing all together, 120 tons; the engineers measured a downwards deflection of the bridge roadway of 0.205 inches (0.5 cm).

The northern bascule bridge was built in 1972, parallel to the swing bridge. It was built by a Sheffield company who used aluminium for part of the structure, to reduce weight. The lifting section is 17.28m long with a carriageway width of 6.7m and a footway on the outside edge of the parapet of 2m.

Major remedial work has been carried out on the two bridges from September 2006 to May 2007 causing long traffic delays in a contraflow system. The bascule bridge was covered for many weeks to allow repair work to take place in the dry.