In order for the Drive One app to see where you are driving and thus give you the alerts that you need, you need to allow the Drive One app to access your location data. 

If you have not given it access to your location data, the Drive One app will not work as intended. 

When you start the Drive One app, it will check whether Drive One has the needed permissions. 

If you do not give Drive One permission to view your location data, you cannot use the Drive One app and it will not start up correctly.