If the parking garage or lot is full, it makes no sense to let additional cars enter. So the ticket dispenser is de-activated and the Lot Full Sign indicates to the propective parking customers that there is no more space in the garage. As soon as some vehicles leave the garage and space becomes available, this process is reserved.
The iWatch Lot Full Sign uses hi-brightness LEDs that are very clearly visible from up to 50 feet distance in most lighting conditions. It is housed in an outdoor enclosure and is mounted about 10 feet in front of the parking patron.