Zipcar's Information Infrastructure

by IntlOrange

Zipcar is the largest car-sharing company in the country, and, while their marketers promote the size of their fleet, I'm more interested in the hidden information infrastructure that makes it all possible.

Reluctant to do anything that could jeopardize my membership, I've made some inferences about how their systems work without resorting to hacking any of their hardware (i.e., damaging vehicles).  These stories of "edge cases" should illuminate some of their systems' inner-workings.

To those unfamiliar with Zipcar's car-sharing model, it works like this: Customers pay an annual membership fee (around $50) in exchange for access to Zipcar vehicles, which are parked in designated spaces in urban areas.  Cars must be reserved in advance (although it could be as little as one minute in advance), and reservations can be made by phone or online, through the website or a stripped-down mobile interface.  Reservations may be for as little as one hour or for multiple days.  To access the vehicle, you hold your RFID membership card over a sensor installed on the driver's side of the windshield.  The car verifies that you have reserved it for this time, and it unlocks all its doors.  The keys are already in the car, tethered to the steering column, so you're all set.

In addition to the annual membership fee, customers are charged an hourly rate for using the vehicles, which ranges from $8.50 to $10.50 an hour, depending on the car's cool factor (Mini Coopers are most expensive) and gas mileage (Priuses are cheapest).  The hourly rate includes the cost of gas and mileage up to 180 miles, after which there is a per-mile surcharge.  (There's a gas card in the visor that you can use to fill up when needed.)  Also, when booking for a 24-hour period, a special all-day rate is used, which is about $70-$90.  In short, Zipcar is a great deal; it's much less expensive and far more convenient than regular car rentals when you only need a vehicle for short periods of time every so often.

One time, I went to pick up my reserved Zipcar, but the member before me hadn't yet returned it.  I patiently waited for 15 minutes, and then, just as I pulled out my phone to report the tardiness, the black truck roared into its designated parking space -- with two enormous couches still in its bed.  WTF?  The dude gets out, apologizes, and asks me to help him unload the couches.  Apparently, he was running late and hadn't been able to complete his move.

He asked if I'd reported that he was late yet, and I said no.  (A $50 late fee discourages tardiness.)  I asked him to lock the truck by tapping his Zipcard to the RFID reader so I could then unlock it with my own card, officially starting my reservation.  He basically refused to "check out" of his reservation, explaining that "If they don't know when I returned it, then they won't charge me the late fee."  I didn't have time to argue at this point, so I just took the truck, returned it an hour later, and locked it using my card.

I called Zipcar later to tell them what happened, and they confirmed that, yes, of course, they cannot be outsmarted.  You see, until you lock the car with your card, the clock is still running on your name.  So, in this case, Mr. Late Driver was "on the clock" until I locked up at the end of my reservation.  So he was charged for his reservation, plus a $50 late fee, plus $9 for my hour of driving.  (I still had to pay for my hour, too, which is unfortunate for me, but a win-win for Zipcar.)

During another recent reservation, I lost my Zip card.  I was locked out of my vehicle in rural Western Massachusetts, and it was getting late.  I called 866-4ZIPCAR, where a friendly voice verified my identity (asking for name, Zipcard number, DOB, and address) and then -- ka-chunk! -- instantly unlocked the car.  Yes!  That was all I needed, but the rep directed me to the trunk.

In the area near the spare tire, there was a stack of new Zip cards.  I chose one and read her the six digit code on it.  She linked that card to my account, deactivated the old one, and I was back on the road like nothing had happened.  (I expect to be charged some fees for service rep assistance and a replacement card, but the bill hasn't come through yet.)  The fact that their reservations system communicated so quickly with my vehicle in a remote area tells me that whatever wireless protocol they're using isn't cellular.

Another instance of over-the-air magic occurred when I arrived at my Toyota Matrix only to find it completely scratched, dented, and missing a hubcap.  I called Zipcar, and, after a few minutes of collecting my description of the damage, they reassigned me to another car ten feet away, which unlocked with a wave of my card.

The one part of Zipcar's infrastructure that's not so magical is their billing system.  My normal annual membership cycle runs from December to November, but the last time I relocated (from San Francisco to Boston in June), I spotted the $50 "annual" fee on my credit card statement.  An email to Zipcar elicited the response that it is their policy to re-charge the annual fee when a member moves to a different area.  Great.

I hope these stories have gotten you thinking about all the technology behind the scenes at Zipcar.

Happy car sharing!