They cache your route, so if you lose your connection you're fine. However, if you make a detour it won't be able to recalculate a new route until it gets connectivity again.
If Google can tell where people tend to drop service, they might even decide automatically whether pre-fetching is necessary.
They collect a lot of data from mobile Maps users, so I wouldn't be surprised if they'll give it back in form of all kinds of neat automations/optimizations.
Comments
They cache your route, so if you lose your connection you're fine. However, if you make a detour it won't be able to recalculate a new route until it gets connectivity again.
If Google can tell where people tend to drop service, they might even decide automatically whether pre-fetching is necessary.
They collect a lot of data from mobile Maps users, so I wouldn't be surprised if they'll give it back in form of all kinds of neat automations/optimizations.