A259
In short
The A259 is a major trunk road running along the south coast of England through Hampshire, West Sussex, East Sussex, and Kent.
In plain words
It is a long coastal road that connects several seaside towns. It travels from Brighton all the way to Folkestone, passing through places like Eastbourne and Hastings.
A simple example
A driver travelling from Brighton to Folkestone would use the A259 to follow the coastline.
Why it matters
It is the longest Zone 2 A road in Great Britain. It serves as a vital link for local traffic and tourism along the English Channel.
Easy to mix up
Do not confuse it with the A26, which is a different road located further inland.