Noise map of Kent
Dear reader, those nice people at the CPRE have produced some maps that are both pretty and informative. They show the distribution of "Tranquility" across our fine nation, and come with an explanation of how the CPRE assess tranquility.
Looking at the map of Kent (click it to big it) the cities and towns are easy to spot, as is the M20 running through Ashford to Folkestone, and the roads radiating out from Canterbury.