I live a 5 minute walk from Blackwater station and have read this thread with interest.
The North Downs is an unusual line and, whilst the Gatwick flow is important, it is not a consideration for most users.
In addition to normal local traffic, Reading, especially, and Guildford are prime commuter destinations in their own right.
There are London commuters from Blackwater, Sandhurst, Crowthorne and Shalford as the journey times are competitive when compared with stations having direct links.
The line cuts across several London lines and so opens up a huge number of journey opportunities across southern England without having to go near London - via the interchanges at Reading, Wokingham, Farnborough North, North Camp, Guildford, Dorking Deepdene and Redhill.
There are significant numbers who use the North Downs to access the Reading hub for longer distance journeys to the west and north, with the benefits of avoiding London and, in many cases, faster end to end journey times. It's noticeable that my local station Blackwater, which has a prime, accessible location at the north end of the Blackwater Valley conurbation, is well used as a gateway for this purpose by people living in Camberley, Frimley, north Farnborough (Farnborough North station should really be called Farnborough East!) and Yateley.
The current service pattern, unchanged pretty much for years, is about right. Given the current impossibility of a more frequent direct Gatwick service the only tweaks I would make are:-
- An earlier first stopping train to Reading (taking the path held by XC?)
- Address the mid-evening service gap from Reading between 20:04 and 21:34 (the 20:34 is a semi-fast, so passengers for Crowthorne, Farnborough North etc have a long wait)
- Restore the 3tp2h Sunday service for stations between Reading and Guildford between 10:00 and 17:00, as the combination of Reading and Guildford shoppers and Gatwick passengers can result in third world-style overcrowding on current services.
As for the long term future, I think the line has to continue as a diesel island until either the Waterloo - Reading and Redhill - Gatwick stretches have been converted to OHE or battery technology becomes proven and cost-effective. Whichever way, I cannot see the current situation changing anytime soon.
Thoughts of Oxford - Gatwick directs etc, even if desirable (which I would question) are not practical propositions, and Oxford passengers already have perfectly good direct services to Birmingham and Southampton airports.