Hi Chengke,
In that paper the problem was that the countings were split between
two directions. In some cases the directions (with one or more lanes)
were divided by physical barriers, in others no. In the end we opted
for simplifying the map and summing up the countings - assigning all
countings per direction / lane to a single axial line representing all
directions and lanes.
The axial map will generate a "spatial value" for you. If you create
several lines they tend to have more or less the same integration
value if the system is big enough. That is why multiple lines may not
improve the representation.
However, if you comparing lines with flows and, you can either:
1) discard two stations
2) create extra lines for each station
3) assign the sum all stations to a single axial line (if this make
sense in the whole map)
Apart the number of stations, there is still the number of lanes,
which provokes the same type of distortion. One station may have more
lanes than another.
The best option would be the one more consistent with the whole map.
Therefore, if the multiple lines is a specific case of few major roads
this should not create distortions.
This subject is not very well explored, It might be the case to test
and compare all approaches.
Regards,
Lucas Figueiredo
On 08/01/07, Chengke LIU <[log in to unmask]> wrote:
> Dear all,
>
> Thanks all for your valuable advices. As Lucas Figueiredo told me to keep
> the simple way when drawing the axial map, but how to deal with the
> situation in the attached demo figure, how to assign the traffic volume of
> the counting stations to the axial lines? Should I snap all those 3 stations
> to the highlighted axial line? Do you snap the stations to the nearest axial
> line in your paper (Figueiredo, L., Amorim, L., 2004, "Continuity lines:
> aggregating axial lines to predict vehicular movement patterns")?
>
> I am looking forwards to hearing from you. Many thanks.
>
>
>
>
>
--
Lucas Figueiredo
Mindwalk
http://www.mindwalk.com.br
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