Those arguing for an offline dual carriageway between Lewes and Eastbourne usually start with its alleged economic benefit, never as yet publicly proven.
The reality is that the A27 is mainly a commuter road. Only 15% of its traffic is good vehicles.
Greater Eastbourne is a dramatically cheaper place to live for those working elsewhere in East Sussex and beyond - the average house price is £239k, compared with £320k in Brighton Kemptown, £327k in Lewes, £332k in Wealden, and £360k in Brighton Pavilion.
Under-provision of good public transport leads to more car use. Wealden tops the A27 East constituencies, with 69.8% of the population using a car to get to work. Compare that with Brighton Kemptown, where 49.5% use a car.
If councils were measured over-time by how much they've reduced single-driver car journeys and their consequent pollution, we might have a different approach to the development of this lovely part of the world.