When using Waze, the initial projected arrival time is almost always incorrrect. As I drive, it continues to add time to my drive even though there is no traffic and I am going over the posted speed limit. The navigation calculation should be based on the posted speed limit and if traffic is bad, it should be accounted for. The way the app currently works, the calculated time is impossible even if you are speeding, which causes unnecessary stress and causes people to be late unnecessarily.