Quote Originally Posted by DRw2ge View Post

I believe the routing algorithm are all Garmin's... The GPS just takes raw data from "whatever" source you feed it (i.e. Google) and "recalculates" it and lays down the the route based upon:

A.)Garmin Internal routing algortihms (laying it onto your internal mapset in your GPS)
b.) as well as your chosen "routing preferences" in your GPS. (They come into play if you don't have a ton of viapoints forcing everything

What do you think?
Garmin's routing algorithms frequently change when there is a map or firmware update, and they are not always the same from one model to the next.

One reason I like to route by waypoints is to find roads I haven't been on before. I've been covering close to 50K miles a year for the past 35 years doing field service in New England -- and I loved getting dumped on rural tertiary roads in the less densely populated places.