Eighty-one per cent of Greater Manchester's population does not live in Manchester, sixty per cent of the West Midlands county population does not live in Birmingham, and sixty-five per cent of West Yorkshire's population does not live in Leeds.
And it is widely accepted that long distance rail passengers are interchange-averse (even if the correspondance takes place within the same station).
So what does this mean for high speed rail?
In the case of HS2, additional interchange penalties come with the territory, because fewer access points inevitably lengthens the local leg component of a typical journey.
The use of geographically separate stations for high speed rail exacerbates its generalised journey difficulties. Box 2 of the February 2010 HS2 Ltd Demand Model Analysis attempted to answer the question, 'What is Generalised Journey Time?'
The generalised journey time or cost of travelling represents the total inconvenience of travelling between any two places expressed in common units of time or money. In the case of rail, this includes the total time taken for the journey including any time getting to and from stations or time spent waiting for a train. It also includes additional penalties if an interchange is required (in PLANET Long Distance this is equivalent to half an hour journey time penalty), for having to wait for a train, or if the train is crowded. This represents the fact that people would prefer not to change trains, and dislike waiting for a train and having to spend time on crowded trains. In addition the generalised journey time includes the financial cost of a making a journey, expressed in units of time. The conversion between time and money requires an understanding of the people put on being able to save time, a concept known as their value of time.
It was no surprise that January 2013's hype campaign for the phase two HS2 network ignored the issue of interchange penalties. Applying the 30-minute PLANET Long Distance penalty to Spinkansen phase two would have grave consequences for the proposed Meadowhall station, and fatal consequences for the Toton and Bickenhill parkways.
It would also have substantial impacts on the Birmingham, Manchester, and Leeds terminals. If HS2-eschewing classic services ran through to places like Bradford, Huddersfield, Rochdale, Bolton, and Walsall, their generalised journey time performance would be better than that of HS2 itself.