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. History Turnpikes The A4 has gone through many transformations through the ages from pre-Roman routes, Roman roads (such as the one passing Silbury Hill), and basic wagon tracks. During the Middle Ages, most byways and tracks served to connect villages with their nearest market town. A survey of Savernake Forest near Hungerford in 1228 mentions "The King's Street" running between the town and Marlborough. This street corresponded roughly with the route of the modern A4. In 1632, Thomas Witherings was appointed Postmaster of Foreign Mails by Charles I. Three years later, the king charged him with building six "Great Roads" to aid in the delivery of the post, of which the Great West Road was one. It was not until the 17th century that a distinct route between London and Bristol started to resemble today's road. During the 17th century, the A4 was known as the Great Road to Bristol. When Queen Anne started patronising the spa city of Bath, the road became more commonly known as Bath Road. Over the years, the direction of the road has taken many detours depending on such factors as changes in tolls or turnpike patronage. For example, in 1750 the toll road from London was altered to go through Melksham; and in 1695 the map maker, John Ogilby, produced a map of the Hungerford area of the Great West Road showing two possible routes. As Bath became more popular with the wealthy and famous, it was inevitable that turnpike trusts would be set up under the terms of the Turnpike Acts to pay for maintenance and improvements to the road. The first turnpike on this road was between Reading and Theale in 1714. Due to increasing traffic, sections of the road between Kensington, over Hounslow Hill, to Twyford were turnpike by 1717 with the remaining sections placed under turnpike trusts. As