Pre - 1978, the line was used by services between London and Coastal Towns such as Bognor. The coming of the airport at Gatwick soon put paid to this though and they were diverted away, replaced by semi - fast's and stoppers.
You do still get the odd weekend diversion down the Mole Valley. The next one is scheduled for Sunday 16th September, with the hourly VIC - BOG running non - stop Clapham - Dorking - Horsham. It looks to be a bit of a slow run, stuck behind stoppers most of the way, although the returns look to be making use of the rare Reversible Loop at Streatham Junction. The Sunday just gone, an hourly service ran from Dorking - Horsham as the Cycle Race came to Boxhill.