The A3807 number is allocated to the Taunton Third Way in Somerset. The road was completed in 2011, mostly from existing local roads.
Starting at traffic lights on the A38 Wellington Road the A3807 heads eastwards along Castle Street between Tesco and Lidl, before passing other town centre car parks. The road then turns right at traffic lights then TOTSOs left at the next set onto Tangier Way to cross the River Tone. This is a new bridge built to carry the road, and the main reason why the route became classified, as it provided a relief road around the west side of the town centre. Tangier Way was previously a dead end, built many years earlier in anticipation of the bridge. After passing the former Lidl store, the road ends at traffic lights on the A3027 Bridge Street, named after its own crossing of the Tone just to the right.