On 3/28/2012 6:58 PM, Hilton Long wrote:
Has a set of standard queries been developed to make Tiger shapefiles
routable? It would need to eliminate gaps and ensure that all end nodes
and intersecting nodes corresponded with each other.
This might be better asked in the pgRouting list, but I'll address it here and cc that list.
I have loaded tiger data into pgrouting and you do not need to mess with the end points, just run the just process it like any shapefile and it will work for want it is worth.
The issue with Tiger is that the data is not really suitable for routing, I was using it for drivetime analysis where the results are approximate and that worked fine for my use cases.
Here are some of the problems with Tiger data:
* segments are not flagged for oneway streets
* there is no zlevel information at intersections ( so it will generate routes like drive to an overpass and turn right onto the underpass )
* the road classifications do not allow you to set the average speed for a road class very accurately, although this is minor compared to the first two.
-Steve W