A comment about range-estimation software being mislead by prolonged changes in elevation (http://www.teslamotorsclub.com/showthread.php/3093-Nissan-Leaf?p=62302#post62302) lead me to thinking about how navigation technology could link in to range estimation software. If I have a route that is 100 miles on the motorway at 80MPH followed by 20 miles on a slower road at a steady 50, the satnav ought to be able to tell the car that it expects my power usage to drop, rather than it assuming I'll continue to use the higher power. Similarly, if I've told it that I have to climb and then descencd a large hill, it ought to be able to cope. One could also imaging having metadata in a sat-nav that described the road surface characteristics if this signficantly affected range. If all EVs shared speed, power and location usage, it ought to be possible to compile a database of road resistance that could be used. Satnavs already calcualte 'economical route' based on ICE-specific algorithms, we just need an app to do it for EVs. What other information would we need to do this? What else would we need in the way of EV-specific navigation software? Routing via charge points and booking ahead via the web I have heard of before, but what else might there be?