A3 connects London and Portsmourh, passing close to Kingston upon Thames, Guildford, Haslemere and Petersfield.
Known as Portsmouth Road it’s importance is reflected by the importance of the two cities connected by A3: London, the capital of United Kingdom, and Portsmouth, a significant naval port for centuries, that even today is the only British city with a population density higher than London (13.330 inhabitants for each square mile, compared to 12.910 inhabitants for a square mile, in London).
