Old Oak Common interchange timings
This chart illustrates some of the interchange possibilities from several northern towns⁄cities. Some of the time savings are significant. Some journeys via HS2 and OOC could be quicker still, as I have assumed a conservative 15 minutes to transfer from HS2 to Crossrail services and 20 minutes for less frequent GWR longdistance services.
For some of the current service timings, there may be quicker routes, but I have discounted those which require more than two changes, providing only marginal gains, and have discounted any for which there are only one or two services per day.
For journeys heading west, I have assumed a time of Paddington minus 5 minutes; for services heading east, I have assumed Paddington plus 5 minutes, to take into account the distance from Paddington station to Old Oak Common.
For Manchester Piccadilly and Glasgow Central timings, I have used the HS2 phase 2b times, with HS2 constructed to Manchester Piccadilly and the Golborne Link just south of Wigan, although both will see improved journey times once HS2 phase 2a is complete.
Liverpool and Crewe journey times will remain unchanged from phase 2a to phase 2b (unless Northern Powerhouse Rail provides a link from Liverpool to HS2 at Altrincham).