This would share the existing hardly-used freight line corridors that join Park Royal/Wembley to Brent Cross, Colindale and West Hampstead, and the old railway trackbed to Mill Hill East.
(The map here was originally published in Transport for London's 'Transport 2025' document.)
Below is a London Development Agency (RIP) map of north London development areas. There is no fast and reliable east-west travel in these outer London boroughs. The lack of an orbital, east-west railway in outer north London can be clearly seen:
To the west of the boroughs in the LDA area above, this Brent Council map below shows Brent Cross in the east, and a possible 'North and West London Light Railway' (here called the 'Brent Cross Railway'). Most of the possible light-rail extensions beyond Brent itself are not shown.
(A different 'Phase One', from Brent Cross Northern Line station, via the shopping centre, to either Hendon or Cricklewood Thameslink stations, would perhaps be more likely.)
|Click to enlarge|
|Link to 'lrta' web site|