On 7 May 2004 at 21:49, Alan Penn wrote:
> Can you tell me whether there have been substantial
> changes in relative flows between different streets within the zone?
There have been substantial changes in relative flows between streets
inside and outside the zone.
Beyond that, there's very little I can say for two reasons. Firstly,
this is a politically sensitive subject and we are now in the pre-
election period in London. Secondly, I was only peripherally involved
with any of this work, and am not able to provide full information:
my colleagues will be able to give better answers.
However, I can assure Alain Chiaradia that the four-stage model has
been a dead horse for quite a while now. That doesn't mean that
people have stopped flogging it, but it's not a runner I'm betting
on. And in my employer's house there are many mansions.
re Willumsen's suggestion: an interesting possibility - instead of
calibrating a model based on observations, calibrate an intermediate,
qualitatively different model based on those same observations, and
then calibrate your main model based on the intermediate model's outputs. Hmmm.
One of the great things about being a modeller is that people will
pay you to wilfully over-complicate things ;-)
Andrew
(writing in a personal capacity in this and my previous email)
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