But if you use such apps, it still rarely shows Thameslink as a better alternative, why? Because the terrible connectivity of Thameslink to tube lines means you often have large time penalty taking it.
If we consider people like me who live on the southern Northern Line (Morden-Elephant),
changing at Elephant & Castle from the Northern Line to Thameslink would add a 5-10 min time penalty, including walking outside in the rain in a pretty unsafe-feeling area.
For the large flow that is heading to Canary Wharf, there will then be a second time penalty if they take this route, due to the indirect connection from Thameslink to the Jubilee again at London Bridge.
So Thameslink offers no benefit to us. It's always easier, quicker and drier to stay on the Northern line. Thameslink also has no connection to the Central Line, the Northern Line has two at Bank & TCR. Northern Line therefore wins again for people heading East or West.
Bref, the reason Thameslink isn't used by many London commuters isn't because it isn't on the map; it's because it isn't a direct or useful service for the journey they need to make.
Had they built better, in-station direct connections, at say Loughborough Junction with the Overground, Elephant & Castle with the Tube, a Central Line connection, maybe something on the Edgware branch near Belsize Park, then I'd hazard a guess patronage would be much higher, and it might have helped ease the awful overcrowding we have to deal with.
But the inability to see the need for good connections seems to be a disease that this country's infrastructure planners ever since the Victoria Line was finished. As we've now seen again with Thameslink.
Really? Yes, connections could be better, but it's the best-connected railway in London, Crossrail will make it even more so.
Within the zones you've got:
Purley (Southern)
East Croydon (Southern, Trams)
Norwood Jun (Southern, ELL)
London Bridge (Southern, SE, Northern, Jubilee)
Wimbledon (District, Trams, SWR)
Mitcham Jun (Trams)
Streatham (Southern)
Sutton (Southern)
Tulse Hill (Southern)
Herne Hill (SE)
Greenwich (DLR)
Woolwich Arsenal (DLR)
Abbey Wood (Crossrail)
Denmark Hill & Peckham Rye (SE, Southern, ELL)
Nunhead (SE)
Catford (OSI Catford Bridge SE)
Shortlands (SE)
Bromley South (SE)
Orpington (SE)
Swanley (SE)
Elephant & Castle (OSI Northern & Bakerloo)
London Blackfriars (Circle & District)
City Thameslink (unadvertised OSI Central, not that useful after Crossrail)
Farrington (Circle, H&C, Met, Crossrail)
St Pancras (Circle, H&C, Met, Northern, Piccadilly, Victoria, King's Cross, Eurostar, EMT)
Kentish Town (Northern)
West Hampstead (OSI Jubilee, NLL)
Finsbury Park (Picadilly, Victoria, GN)
Redhill (GWR, Southern)
Gatwick Airport
Thameslink makes most of South London accessible with one-two changes.
Elephant isn't the best connection, but it isn't awful, I'm not sure about feeling unsafe there these days; it's being gentrified and developed beyond belief with the shopping centre going and everyone from the Haygate pushed out. I'd be surprised if the stations are integrated soon enough. I know it had quite a bit of support for the Bakerloo extension.
The only connections really missed is the Sydenham corridor (which is mad), Alexandra Palace and Loughborough Junction. L Junction isn't really an issue as there are direct Thameslink trains from Denmark Hill & Peckham Rye. Belsize Park is impossible as it's in the rather long Belsize Tunnel which came first.