Parking lots and municipal areas alike rarely have enough parking spaces to accommodate all the vehicles of everyone who wants to visit. Posting time limits for parking as well as fining those who remain too long helps ensure that vehicles don’t monopolize parking spots. Enforcing those limits typically means manually chalking a vehicle’s tire – making a small chalk mark on the tire. If parking enforcement finds that chalk mark after the parking time limit has expired, it means that the driver has overstayed their welcome and can be fined accordingly.

Chalking vehicle tires, however, is a time-consuming, labor-intensive operation. Parking enforcement officers must walk up to every vehicle and make the chalk mark themselves. Later, they must slowly inspect each vehicle for the chalk mark. And they must trust that drivers are not erasing chalk marks or only moving their vehicle a few inches to hide the chalk mark. In short, despite its long use as a parking enforcement method, there are many downsides to the approach.

And there’s another more pressing concern: chalking tires may be illegal. In Taylor v. City of Saginaw, the 6th U.S. Circuit Court of Appeals ruled that chalking tires was a violation of the Fourth Amendment’s protection against unreasonable search and seizure of property. The case focused upon the physical act of chalking vehicle tires, which was ruled trespassing upon private property without just cause.

Fortunately, there is a more efficient, reliable, and law-abiding solution: digital chalking.

Digital chalking makes use of cameras and vehicle recognition software (VRS) to, at a minimum, records the time when a vehicle parks as well as the location of the valve stem on one of the vehicle’s tires. The valve stem location replaces the chalk. After the parking time limit has passed, the system checks the valve stem location again. If the valve stem location has not changed, that would indicate that the vehicle has remained in its parking spot beyond the allotted time limit, and the driver can be fined.

This example is the most basic application of digital chalking technology. More sophisticated systems can also record the vehicle’s license plate, color, make, and location via GPS. All these data can be used to confirm that the vehicle has remained too long in its parking spot. The technology can even connect directly to DMV databases to create and deliver parking citations electronically.

How might such technology be deployed? In parking lots, it can be done with stationary cameras that are triggered once a vehicle pulls into a parking spot. The VRS then records the necessary data and begins timing the vehicle’s length of stay. In parking lots, the use of the valve stem imagery may not even be necessary, as the software can simply identify when the vehicle comes and goes.

In on-street parking applications, stationary cameras can be used. However, many parking enforcement organizations prefer to use either a mobile camera mounted in an enforcement vehicle, or a handheld camera used by a parking enforcement officer, such as that in a smartphone. In either application, it is the technology that does the heavy lifting. As the parking enforcement vehicle makes its rounds – or the parking enforcement officer walks their rounds – vehicle data are recorded and timestamped to confirm whether the vehicle has stayed too long in its parking spot.

The result is a more efficient system with higher reliability. That means less work for parking enforcement officers and fewer drivers who are able to cheat the system.

Even better, this approach is not a violation of Fourth Amendment rights. After the Taylor v. City of Saginaw decision, University of California, Berkeley law professor and Fourth Amendment scholar Orin Kerr weighed in on Twitter by saying, “…seems easy enough these days for parking enforcers to just take a photo of the car, or even just a close-up photo of the tire, rather than chalk it. That way parking enforcement can learn the placement of the car w/o physically marking it. No 4A issues then.”

Do you think such a solution might work for you? Contact your omniQ sales representative. They will be happy to assist you in figuring out what application of digital chalking works best for your application.