Stoppage reports lets you access the Stopped Time Summary of phones (by group) based on your 'minimum stoppage time' criteria (e.g.: you can set the report to only include stops that are more than 10 mins).
Here is how:
Navigate to the 'Phone Group' under the 'Reports' section.
Select the 'Driving/Stopped Time Summary'
Select 'minimum stoppage time' criteria (e.g.: the screen above shows 'Based on 10 minute minimum stop').
Select the Group, Date range, and the format and hit 'Get Report'.