[pgrouting-users] Thoughts on how elevation in routing

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