I am passionately interested in public transport, so I am a member of the Campaign for Better Transport (CBT), Bus Users UK and Railfuture.
Not one of those organisations has a branch in rural West Sussex but a number of rail commuters are members of Railfuture.
The CBT has branches in some other parts of Britain, especially in National Parks, but none in West Sussex.
I wish that some of the recent cuts in public transport would be reinstated. I used to catch the Worthing to Chichester bus, get off at Arundel for half an hour or so, then get the bus to Coldwaltham, the village where I grew up. This is no longer possible even though the A27 main road gives opportunities for fast travel, at least as far as Crossbush.
There really should be daily buses between Pulborough and Littlehampton via Arundel, the reinstatement of the demand-responsive minibus and a better service between Storrington and Arundel, among other improvements, as befits a National Park.
I think the Peak District, Snowdonia and the Lake District are among the best national parks for public transport, even though the South Downs park is probably the richest.