A Theoretical Vector for Achieving Free Parking on N.C. State's Campus

Recently (this semester) my university, N.C. State / NCSU, has implemented some changes regarding on-campus parking passes and parking enforcement. The most notable changes are only two in number:

  1. Sticker passes are no longer distributed
  2. Passes are allocated per-term (instead of per-year)

(1) simply means that all management and distribution of parking passes is handled on-line through the NCSU Transporation Office (a department of Environmental Health & Public Safety at State). Although the parking rules have not changed recently I will list them here for completeness:

  1. Persons parking on-campus during school hours must own a (virtual) parking permit
    • Equivalently, nobody parking on-campus during school hours may not own a (virtual) permit
  2. One permit specifies exactly and only one car which is allowed to park on-campus
  3. Cars which are parked on-campus during school hours which are not specified by any permit are liable to be fined / towed (depending on location)
  4. License plates must be clearly displayed according to the following rule:
    • Cars choosing to pull-in (rear-end facing the road) must have the (state-issued) license plate mounted to the bumper, not displayed in the window
    • Cars choosing to back-in (front-end facing the road) must purchase and mount a vanity plate which indicates the car’s plate number

Parking is enforced almost exclusively by patrols dispatched by the Transporation Office at NCSU; because of the number of and distance between the parking areas distributed across the Centennial and Main campuses, these patrols employ cars and trucks with some kind of license-plate scanners. It is a high-likelihood that these scanners use optical character-regognition (OCR) to rapidly scan license plates while the vehicle cruises around the lot; the rapid flashing of the orange light atop the scanner (which itself is atop the enforcement vehicle) suggests that a car / truck cruising at (the typical) 5MPH may take upward of 15 ~ 20 samples of a car. Foot-patrols are an extreme rarity, and the patrolwo/men will only exit the vehicle to issue a ticket.

Because the rules of parking enforcement have been explained I will now introduce the (proposed) vector to exploit free parking on NCSU’s campus.

Attack Vector Statement

The vector I suggest is simple: consider the following lemma:

  1. It is impossible for a single patrol car to patrol more than one lot,
  2. A vehicle owner is free to drive and park in different lots as s/he pleases
  3. Then it is possible for that (registered) plate to show up in two disjoint lots at roughly (but not exactly) the same time

(2) follows from the notion that an owner may drive a car from one recently-patrolled lot to another soon-to-be-patrolled lot. This does not raise any flags in the Transportation Office’s system and is actually a regular occurence. The absurdity of this occurence increases as the split-time between patrols of those lots decreases, though I doubt anyone would notice if the same car were clocked at two disjoint lots at exactly the same time; this would warrant (because the sheer number of cars prohibits inspection of each and every plate-reading by hand) that the Office is using well-written software which thoroughly considers edge-cases like this (which is doubtful as well).

Next I use the above lemma to propose the attack vector:

  1. Consider a car (either back-in or front-in) with a registered plate number A
  2. Next consider a different car (backed-in) with an unregistered plate number B
    • Implicitly B≠A; this follows from the North Carolina vehicle registration restrictions which prohibit two vehicles from sharing plate numbers
  3. Suppose that the car with plate B sports a vanity front-plate displaying A
  4. Then both cars appear to have valid permits (albeit the same permit)
  5. Then neither car will be ticketed

The above demonstrates how an unregistered car which is not associated with a valid permit may park on-campus during school hours without receiving a parking ticket.

Practical Considerations

Now that the groundwork for exploiting this vector has been exposed I will now explore a few practical examples for achieving free on-campus parking.

The pivotal statement in the above proof is (3); a vanity plate is chosen because it is explicity illegal to modify one’s rear license plate in the US. Although there are 31 states in the Union which enforce the attachment of a front-plate (which similarly cannot, by law, be modified) North Carolina is not such a state. Many people in NC choose to affix “vanity” plates to the front of their cars instead: sports teams, company logos, and things like this are common choices.

But however “legal” it may be in NC to affix a vanity plate reading a license plate number which is not yours, generally it does not seem desirable and you will definitely be pulled over for having one should you ever leave the state (and it’s likely you’ll be pulled over here too for “obstruction of justice” or similar).

The solution I propose is to sport a concealable vanity plate (maybe by means of a sliding door or latch); when not concealed the license plate could read “Go Steelers!” or something but when opened it reveals a vanity plate number corresponding to a valid parking permit. The idea is to open the plate when you enter the parking lot and close it when you exit.

You still need to find a valid plate number to masquerade as, of course. This is actually trivial because any car parking in a parking lot during school hours will have a plate associated with an active parking permit. It is worth considering that any given plate, while valid for the current term, may not be valid for the coming term. Thus this strategy works only for one semester reliably (at most 5 months).

Cost Analysis

Following is a breakdown of all costs associated with parking permits for the Fall 2019 term:

This is counterbalanced by the cost of a (university-sold!) vanity plate:

Considering the volume of plates being checked by the patrol cars it is considerably unlikely that your car will ever be looked at with any degree of scrutiny if it passes as a valid plate. Considering this, the attack vector pointed out here is extremely lucrative ($5 one-time vs. a recurring $210 /sem.) and thus important to understand.