There are some gates which can be very long, the one shown in the photo is 24m !

This requires a large industrial sliding gate operator and because of the size of the gate, a chain drive was selected.
The advantage of chain drives and belt drives is if the track is uneven or on varying slopes, it does not affect the drive operation at all.
This gate opens many times per day, sometimes even when a pedestrian exits, which seems rather unnecessary to have a 24m gap to walk through !

However, the GDS Industrial slider can do this.