Bicycle GPS systems suck at planning routes!

[cowtsign]

I recently indulged and bought a bicycle GPS system (Garmin Edge 705) and maps (which you pay $200 extra for as Garmin is stingy) and I've found that it can't navigate! Firstly by the default settings it avoids all major roads (thankfully you can turn this off) which means that if you follow the directions it will tie you in knots avoiding them. Secondly it doesn't understand rivers...

I think it plans routes by doing the following:

1. Sampling roads that intersect a straight line to the destination
2. Searching outwards from the sampled roads to join them.

This is bad because it means that if you have a major river that curves through the straight line path (one which you would normally follow rather than crossing) suddenly you're going huge distances out of the way to find river crossings!

So anyone thinking of buying one of these devices take note that you will have to pre-program any routes or they had better be in a straight line avoiding major roads.