Semington Aquaduct was opened in 2004 to carry the Kennet and Avon Canal over the new
Semington Bypass which carries the A350 on its way from
Chippenham to
Westbury.

Semington Bypass from the Aquaduct
Although the A350 is a Trunk road funded by the Department for Transport, Wiltshire County Council took an active role in its promotion, and indeed their transport Supremo performed the opening ceremony.

Semington - plaque
The Aquaduct is quite a feat of engineering, with nationally known architects and construction companies involved in its design and implementation.

Semington Aquaduct - road and water
The A350 passes under the waterway. Note that the canal
widens out into a waterway dual carriageway over the aquaduct - perhaps there's some advanced planning for a heavy increase in boat traffic.

Semington Bypass
Road traffic is already heavy under the aquaduct, although I doubt than many of the drivers realise they're passing under the canal.
Map locator - Semington_Aquaduct