Loading as fast as ever on my end. Even faster than Google maps, in fact.
Are you on the latest version of iOS 10? Beta or not? Which device? Tried resetting network settings? If you do that last one, you will have to enter your WIFI credentials again, so keep that in mind.
EDIT:
https://forums.macrumors.com/threads/gps-problems-iphone-7-or-ios10.1998933/
There seems to be a discussion (maybe?) related to your problem in this thread as well.