Good question… Think I might have encountered one as a scenario where you get diverted off the Quarry Line but without checking the actual IRL timetable couldn’t be certain. It’s like the slow lines from Clapham to Croydon, never yet encountered a driveable service that uses these.
I just checked the timetable made by WonterRail (which you can find in the creation centre) and there are no services between London and Brighton via Redhill. The only trains that stop at Redhill are the 377 London-Reigate services and - if you are playing on pc and own the 166 - the Gatwick-Reigate services. There are also Lovers Walk-Selhurst TMD moves run by the 313 that run through Redhill but they are empty stock workings and mainly run during the night when there are no other trains around.
Just checked RTT and there's only one service a day which goes from Victoria to Brighton which also calls at Redhill. There's only one other that calls at Redhill and then onto Brighton and that's an early Thameslink service.
Welcome. It's not unusual for these "minor stations" to not have service that goes to each end of the line. Far more people want to go from Redhill into London than down to Brighton or from Brighton to London than to Redhill... Gatwick and Three Bridges would be the interchange stations for this one --- I say minor, Redhill had 4.5 million passengers through it in the last ORR figures
