[pgrouting-users] Thoughts on how elevation in routing

[Stephen Woodbridge]

Hi all,

I have preprocessed some shapefile data and added elevation information 
in the Z value of the coordinates. I'm wondering how to best utilize 
that in routes and would like any thoughts or ideas you might be willing 
to share.

The obvious answer is to wrap the elevation data into the cost values as 
this is simple and straight forward and does not require code changes. 
This brings me to what have other people done or thought about doing in 
this regard?

Here are some random thoughts I have had on this in no particular order:

o for bicycles, we probably only care about UP grade and length. This 
would imply that segments need to be in a directed graph with different 
costs going from A-B vs. B-A based on the upgrade

o for trucks, maybe an un-directed graph is ok, because they need to use 
low gear both up and down depending on the grade and length

o for motorcycles, hilly terrain tends to mean more twisty roads which 
are more fun to ride so lower costs for roads with lots of elevation 
changes.

grade = (rise / run) * 100

where run should be the 2D length of the segment.

Is there a "standard" way of factoring grade into the route calculations?

Thanks,
   -Steve