A303

The A303 is a major trunk road in southern England, designated as part of the country's Strategic Road Network. It runs from the M3 motorway near Basingstoke in Hampshire to the A30 at Honiton in Devon, passing through Wiltshire and Somerset. The route forms an important link between the M3 corridor and the southwest, and it is part of the historic London to Cornwall highway network.

Along its course the A303 serves a mix of rural and urban areas. It passes close to the Amesbury area and the World Heritage Site landscape around Stonehenge, making it a notable route for tourism as well as through traffic. The road also serves towns such as Wincanton, Yeovil, and Ilchester before reaching its western terminus at Honiton, where traffic continues onto the A30 toward the southwest. The A303 carries a combination of long-distance, freight, and local traffic and connects with several other major routes to facilitate regional travel.

The road is maintained by National Highways and has been the focus of safety and capacity improvement schemes over the years. Because of congestion and the sensitivity of Stonehenge and surrounding landscapes, there have been long-running plans to upgrade sections of the A303. A notable component of these plans is the proposed Stonehenge tunnel, intended to divert through traffic away from the World Heritage Site and relieve pressure on the surrounding road network. As with many large-scale infrastructure projects, progress has involved extensive consultation, funding considerations, and procurement stages.