Mine was tripping randomly anywhere between 2 -50 miles at a time. No relationship to the road - it would be fine on a bumpy back road then trip miles later on a smooth dual carrigeway - or visa -versa!
As a temporary fix I cable tied a washer over the top of the switch to keep it locked shut.
Replacing the switch made no differece and I eventually cured it by cable tying the wires leading to the switch to the battery box. I think they were vibrating and wobbling the inertia switch enough to trip it.