Is this the same mechanism for signaling lock/unlock as some moving sidewalks use to lock carts in place on the track to prevent you from pushing them?

One of our local hardware store chains, Menards, have ramps in the form of moving sidewalks to allow customers to get fully loaded carts between floors safely and they seem to very reliably lock to the floor at the start of the ramp and unlock at the bottom. I've always been curious about the mechanism.