Constant recording: To keep constant video recording (maximum clip length is 3 minutes) while driving it is strongly suggested that you certainly turn off "motion sensor" function because it will give false alarms and will not grantee smooth constant video recording.
Motion sensor function is mostly used when car is parked and dash cam is on stand-by state to detect any movement in front of the car for minimal recording time for this mode is 10 seconds while anything alerts the dash cam sensors.