Assuming I'm following a route (so that Waze "knows" where I'm going). When I loose GPS signal (lots of tunnels here in Stockholm) I'd like Waze to assume I'm following the specified route and just advance me on that route based on the base speed of that route (I assume Waze has that info since that must be how the ETA is calculated). Now I'm stuck at the entrance to the tunnel until I pop out at the other end. This is particularly unhelpful when tunnels have multiple exits along the way.

(Apple's mapping app does this as far as I can tell ... although I almost never use it since I always have Waze running).