Free Parking Garage Access

This hack is an interesting twist that will allow you to get in or out of some parking garages when the attendant isn’t looking. Using something metal to trip the parking lot’s proximity sensor that is meant to let cars out automatically you can get into the garage or vice-versa without opening your wallet. A magnet from a hard drive might work a bit better because it is able to trip multiple types of sensors, but for this hack any kind of metal will work. This proximity sensor is a high–frequency oscillation type, so anything that attenuates, varies the frequency or stops the oscillation trips the sensor. When you can’t find a place to park, this hack will certainly impress your friends more than this method, but your street credibility could quickly turn into never lived down stories, if you end up driving over tire strips and ruining your tires, get a huge parking or trespassing ticket, or worse yet get your vehicle towed!

21 thoughts on “Free Parking Garage Access

  1. this hack is nothing new. this way i’m parking every day at university cause there are no parking lot’s for students without payment, the notebook in my bag is enough to get into. no damage to the notebook.
    so i’m parking cheap and secured on the employees parking lot.

  2. that works because the installers were too lazy to do their job right. the sensor isn’t supposed to respond to small metal objects, but its sensitivity depends on how deep it’s buried. If it’s installed at the right depth and adjusted right a tin can won’t trip it, you would need a piece of metal at least a meter square. Looks to me that if you were wearing steel toed work shoes the damn thing would open if you walked across it.

  3. Umm most dont work like this, they require you to get a ticket, and upon leaving pay for your time there. So in order to get a free parking spot with NO risk, you go in (get a ticket) leave and do what you got to do, get another ticket and as you leave use your new ticket so that the time is less than the time you spent there

  4. I usually just social engineer my way out of car parks. Most times all you need to do is pull up to the exit gate, call the security guys over the intercom, tell them you’re a contractor and they usually let you through. So now I have a stack of entry tickets to play around with.

  5. 5, Most carparks(around here) don’t charge for the first 15mins, this it to account for people not being able to find parks. So if you get your self a fresh ticket on your way back to you car you can get free parking. Just don’t forget to smile for the cameras.

  6. “Inductive proximity sensors are suitable for the detection of metallic elements. The operating principle is based on a high frequency oscillator able to create an electromagnetic field in the close surroundings of the sensor. The presence of a metallic object (actuator) in the operating area causes a decrease of the oscillation amplitude. This happens when part of the electromagnetic energy that is transferred from the sensor to the actuator is dissipated by the effect of the Focault Parasitic currents. The oscillation amplitude, therefore, decreases in accordance with the distance between the actuator and the sensor. This provides the sensor with analogic information about the object position (analog sensors) or can be turned, using a threshold circuit, into a digital signal (ON-OFF sensors).” from

    Because of this common type of sensing method the metal does not have to be ferrous, and is why aluminum works.

    I know this will not work in a lot of situations. but for some especially private gates :)

  7. So… any guesses why this would work, when my motorcycle (aka big piece of metal) even including a special magnet that is supposed to trigger these sensors does not do so?

    I frequently cannot even get into the parking lots that I have access to if I am in anything smaller than a car…

  8. There are a couple reasons, in this case the previous commenter was correct the gain is probably turned way up, but most of them are, as this is a common solution when they don’t detect things like motorcycles.

    BUT the main reason is you are not moving fast enough directly over the sensor, notice how he was winging that can and phone around? The sensor needs to see a change. You could park an entire car on there not moving at all and it would not trip. It is all relative are car does not need to move as much as a motorcycle, and the smaller the object the fast and closer it needs to be.


  9. It appears this fool is going in the exit lane of the parking ramp. I’m an attendant at a parking ramp and this would technically work with ours, but I don’t think the empty pop can would work.

    With our equipment (Federal APD) it has two loops – one before the gate and one afterward. The one before the gate is there to activae some type of software trigger: either allow the “push for ticket” button to do something, the card readers to do something when a card is in proximity, or to open the gate at the exit lane. The loop after the gate is there so the system knows when the car is past so it can drop the gate.

    So as I said before, yes a piece of metal could open the gate up, but you’d risk a head-on collision with someone driving down at you at around 20mph.

    Well that might work in some places, especially those with people that don’t speak english very well. At the place I’m at, this wouldn’t work. Any contractors working on the building itself get special slips of paper signed by the building management that authorize the free parking, or they receive access cards that are given out for the time span they work. Also, the building management alerts the parking management to any contractors working. Everyone else has to pay. Even if you did manage to sneak in somehow, you’d need to have a ticket when you left, or you’d pay the lost ticket fee, which is slightly more than one full day of parking. Also, cars left in the ramp for more than a couple days w/o seeing parking management are towed out and then you pay a $350 fee to a towing company. And we frequently get people trying to scam us out of prepay rates, so we’re accustom to people making crap up. It’s easy to spot when they are vague, don’t know anyone’s name, and certainly don’t know any of our procedures they WOULD know if they were entitled to the free parking.

    @Joey Y
    Well at my work, motorcycles have a problem too. That’s why we generally don’t allow them in. Basically, you don’t have enough metal on the motorcycle to keep the loop “activated”. In other words, you bike isn’t long enough. For the few motorcycles we do or are forced to take in, we have them drive around the gates so they aren’t injured.

  10. I wish there were some lightweight way to trip stoplight sensor loops. I sometimes have to run red left turn arrows on my bicycle because the stupid sensor loop won’t detect it and tell the signal to change.

  11. aluminum cans are made of.. well aluminum. And from every thing i remember about aluminum it is not magnetic. and if a ramp is able to read a magnetic feild from the outside of a aluminum can i want to know how.

  12. This is called a free out. It is a piss poor design.. requires at least two loops to catch illegal exits and illegal entry.

    @joey y:

    The motorcycle doesn’t work because of loop sensitivity and loop design. Good loop systems support up to 5 loops… federal apd does not.


    The activation loop you are talking about is called a “Presence Loop” or Loop B. The “Safety/Closing” Loop is called Loop C. In more advanced scenarios (like those supported by Magnetic Automation Gates), a Loop A is used or Backout Loop.

    @nirgal: The reason it doesn’t work is because the loops are designed wrong and you are using Federal APD equipment. It sucks. Magnetic Automation Supports this.. and Federal APD uses Magnetic Automation gates FYI. Their posidrive gate is a copy of a MIB30.

    @jason: Speed has nothing to do with it.. physics are faster than that motorcycle buddy.

    @enigma: I don’t want parking system the parking garage uses but this is considered a “stolen” or “backout” ticket and if it is a truly online system, the ticket will come up invalid when used.

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