Sliding gates often fail to open or close because debris blocks the track, wheels slip off the rail

https://blogfreely.net/sloganbtjp/h1-b-keeping-commercial-sliding-gates-running-in-la-with-track-roller-and

Sliding gates often fail to open or close because debris blocks the track, wheels slip off the rail, tracks shift out of line, or the operator needs a reset after an obstruction is cleared.