[mapserver-users] routing problem

[Stephen Woodbridge]

Kurt wrote:
>    Hi,
> I understand that this may not be the right place to ask these 
> questions. But I think there might be experts here could give me some 
> suggestions. Thanks in advance.
> 
> 1. Is the Dijkstra's algorithm generally used to find the shortest path 
> between point A and B like google maps and mapquest do. If this is not 
> the case, what algorithms can perform better?

There are a bunch of algorithms that have various trade offs. You might 
want to start by looking at pgRouting which does routing from 
postgres/postgis tables. and supports various methods.

> 2. Are there references that detail how to apply Dijkstra's or other 
> algorithms on the digital data (such as Tiger file in PostGIS). What 
> attributes should I look into?

Tiger is not suitable for routing. You can build a network and route 
through it, but do not expect the routes to be drivable. There is no 
information about one way streets, there is no information about zlevels 
at intersections so it might tell you to turn right from an overpass 
onto the street 20ft below because all intersections look flat in tiger.

> 3. Does multi-mode routing problem use the same algorithm? I am 
> wondering if there is any step-by-step guides or references that I can 
> learn from.

Start with pgRouting and that might be a better list to ask these 
questions on.

-Stephen Woodbridge
  http://imaptools.com/

> Thanks again
> 
> 
> Kurt
> Get more out of the Web. Learn 10 hidden secrets of Windows Live. Learn 
> Now 
> <http://windowslive.com/connect/post/jamiethomson.spaces.live.com-Blog-cns!550F681DAD532637!5295.entry?ocid=TXT_TAGLM_WL_getmore_092008>
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users