The card they give you when you park will have your stall number and phone number to call or text when you have your bags. It will have all the instructions you need. It is good to call or text if you want them to know you want to be picked up.
I prefer to text. Then the next driver is looking for you. Give terminal you arrived at and parking stall that is on your parking ticket.
If your at the airport it is best to call/text to avoid a potential longer wait. The shuttles will run if they have someone but if there isn't anyone on either end they dont run. Its a very short wait after you call/text. The airport has a curtesy phone near baggage with phone numbers.
No shuttle comes about every 15min you just gotta know where your parked.
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