This is an extremely convenient option in the Columbia-Presbyterian area. The system they have for check in is very efficient and flows smoothly. Upon arrival, you let them know approximately how many hours you will be staying and they then direct you left or right. I was only staying for an hour so they gave me a ticket punched with the time and directed me to pull to the right. Here I exited the car and left the keys in it. As I was walking out of the lot, I reassured the attendant my keys were in the car and went on my merry way. I then proceeded to have an anxiety attack while I watched the clock at my doctor’s appointment. PHEW! I made it within the hour and had 3 minutes to spare. $ 19, thank you, have a nice day. At $ 19, it WAS actually cheaper than parking at the metro north station near me and taking the train to 125th St, walking a mile across town to the A train, taking the train to 168th St and walking to the doctor’s office… not to mention WAY more convenient. Before you leave, you pay the girl in the booth and then show your ticket to one of the many parking attendants to go retrieve your car. No wait to enter or exit the garage. There are clearly marked signs & arrows directing you out of the garage, where you insert your ticket at the gate to exit. I’m not sure how long an extended stay was, but this was definitely the most cost effective and time efficient way to go. If you are lucky enough to find a parking meter in the area, the ones I found were an hour max and believe me those meter maids are ON it. I witnessed one standing by a car looking at his watch, just WAITING to give someone a ticket.