On Sun, 21 Jan 2007 10:18:10 +0000, Chengke LIU <[log in to unmask]> wrote:
>Deal all,
>
>I have finished drawing axial lines of one district of Hong Kong – Kowloon,
>totally 3004 axial lines. Also I pin-pointed all the counting stations on
>those axial lines. I calculated local integration of axial lines and
>compared it with the natural logarithm of the average traffic flow of that
>corresponding axial line. To my disappointment, the correlation is quite
>poor, r square value is only 0.10. I am not sure why the correlation is so
>poor, the possible reasons are listed as follows:
>
Chengke,
What if r squared values higher than that were the exception and not the rule?
The literature includes only studies for the city of London and for Atlanta,
and the correlations with pedestrian movement are not high anyway. But what
if these correlations were actually quite poor for most cities?
Why are you excluding this possibility?
Rui
>1.The street network in Hong Kong is very complex, I digitized some road
>lines with only one axial lines, since they represents different lanes for
>different traffic direction. And even, somewhere a cluster of roads are
>represented for only one axial line for simplification.
>2.Due to lacking of time and manpower, I did not take those overpass and
>underpass roads into consideration when I calculated the connectivity value
>of axial lines. When I digitized the axial map, I only referred to the
>digital street and building maps of Hong Kong at hand. Some lines are
>apparently intersected on digital map, but actually they are not, since one
>of them is overpass or underpass road.
>3.When I assigned the traffic flow the axial lines, I first pin-pointed
>counting stations on roads to corresponding axial line, and then averaged
>the traffic flow.
>4.The spatial configuration (space syntax) is not suitable in Hong Kong to
>predict traffic flow.
>
>The above factors are responsible for the poor correlation from my point of
>view. What do you think about this problem? Since Kowloon is only one
>district of Hong Kong, I need to continue with the whole Hong Kong
>territory. If something wrong in above 4 factors, please point it out, so I
>can correct it early. Your comments are highly appreciated!
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