The A4 is a major road in England from Central London to Avonmouth via Heathrow Airport, Reading, Bath and Bristol. It is historically known as the Bath Road with newer sections including the Great West Road and Portway. The road was once the main route from London to Bath, Bristol and the west of England and formed, after the A40, the second main western artery from London. Although most traffic is carried by the M4 motorway today, the A4 still acts as the main route from Bristol to London for non-motorway traffic. From Wikipedia
