Yixiang,
In notmal axial mapping one way streets are represened the same as two way. However, if your purpose is to investigate effects of street configuration on vehicle flows then we have found that there are two main ways that one way streets are used in traffic engineering and the map can be adapted to reflect this. The first is where a one way street runs the lenth of an axial line. Usually this is a meth od for increasing the effective capacity of the street. Here you just represent it as a single line in the normal way. The second situation is when alternate street segments along a line run in opposite directions. This means that these segments can only be used as a part of routes on trips running orthogonally across the axial line. Here we find that it is best to break the axial line into separate and on connected segments linking to the cross routes at either end.
Sorry if this is unclear-a drawing helps :-)
For over passes you draw tne lines crossing each other and then use the "unlink" tool to disconnect them in t e graph.
I hope this helps,
Alan
-----Original Message-----
From: "Yixiang Long"<[log in to unmask]>
Sent: 22/07/05 01:33:20
To: "[log in to unmask]"<[log in to unmask]>
Subject: questions about drawing axial map
Hello, All,
I am Yixiang Long, a Ph.D student in North Carolina State University in
U.S. I am drawing axial map of a city for analysing. Nevertheless,I have
some questions about drawing axial map of the city. The questions are
listed as the followings:
1. If the road or street is one-way road, how to draw the lines? the same
as ordinary road or not?
2. There are two roads,not intersecting each other, one road is underpass
or overpass the other road. So how to draw the lines? since they are not
crossed each other.
Thanks
---------
Yixiang Long, Ph.d Student
College of design,
North Carolina State University
Raleigh,N.C., 27695
USA
Phone:919-2333487
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