Unfortunately impossible things that would improve Sub Surface Line capacity:
Reaarange Baker Street Met platforms to be like Aldgate and Edgeware Road with the terminating platforms in the middle
Grade separate Baker Street junction
Grade separate the Aldgate/Aldgate East/Minories junction triangle
Grade separate and rearrange to have terminating trains in the middle at High Street Kensington
Grade separate Gloucester Road junction
Grade separate Praed Street junction
Bonus points if your multi-billion pound rebuilding project under protected buildings and congested streets can furnish the terminating points with reversing sidings for optimum capacity and to make things simpler for passengers
Wouldnt need a grade separated junction at Praed Street/Edgware Road, all you need to do is untangle the flat junction by widening both throats to Edgware Road so 4 tracks leave West of Edgware Road and reallign the Eastern end so the current through track from Baker Street to Hammersmith goes onto the same island as the Eastbound services from Hammersmith with the other island used as a terminating platform with its own run of tracks round to Paddington (Circle/District) that are isolated from the tracks to Paddington (Circle/H&C) so you have 2 independent sets of running tracks however with a flat junction for movements between the Westbound H&C and the terminating Circle/District Eastbound, something like this just i cant do a flat junction:
From Hammersmith-------------------------EBOUND------------- To Baker St
(ISLAND PLATFORM)
To Hammersmith -----------------------WBOUND----------- From Baker St
From Notting Hill Gt ----------------------TERMIN -:
(ISLAND PLATFORM)
To Notting Hill Gt ----------------------TERMIN - :
Something on that arrangement where the 2 approaches from the West are completeley isolated so a late running District Line to Edgware Road wont impact upon an on time running Hammersmith & City Line to Hammersmith by having to hold one to let the other cross over its path
