When GPS signal is lost, especially when in tunnels for like 10 kilometers (like in Paris La Défense highway) currently there is some issues that could be better dealt with I think :
- GPS is stuck on only the next itinerary change when signal is lost. So if you ride for 10 kilometers in a tunnel and the next change is in 4, you don't know what to do after that.
- Arrival time gets delayed as long as signal is lost.

I think it would be better, when GPS signal is lost for more than X seconds, to switch to a different mode, close to the "list mode", as the map gets useless pretty quickly, especially in a jam, where the approximate position is irrelevant.

It would be way more useful to have a list of the 10 next changes (with a picture of the type of change), with approximate time and distance, and be able to check them one by one when you get past them, to keep the itinerary clear and the arrival time almost up to date.