The City of Grand Rapids and many others across the country regularly chalk tires as a means of enforcing parking regulations, but a federal appeals court has ruled that the practice constitutes an unreasonable search which makes it unconstitutional.

The new ruling came on April 22, 2019, from an appeal of the case of Alison Taylor v. City of Saginaw - Eastern District of Michigan at Bay City.

Alison Taylor sued the City of Saginaw and its parking enforcement officer Tabitha Hoskins, alleging that chalking violated her Fourth Amendment right to be free from unreasonable search. The district court agreed with the City of Saginaw and said that while chalking may have constituted a search under the Fourth Amendment, the search was reasonable.

The United States Court of Appeals for the Sixth Circuit, which covers Michigan, Ohio, Kentucky and Tennessee, has reversed the ruling.

The U.S. Court of Appeals three-judge panel says that chalking tires is trespassing "because the City made intentional physical contact with Taylor’s vehicle."

Trespassing is allowed under certain circumstances, but the court of appeals says in this case it constitutes an unreasonable search:

The City commences its search on vehicles that are parked legally, without probable cause or even so much as “individualized suspicion of wrongdoing”—the touchstone of the reasonableness standard.

Previous court rulings have set a precedent that automobiles have a "reduced expectation of privacy," but the appeals court says that does not apply in this case:

The automobile exception permits officers to search a vehicle without a warrant if they have “probable cause to believe that the vehicle contains evidence of a crime.” No such probable cause existed here.

The City of Saginaw tried to argue that it was a public safety issue, but the appeals court disagreed:

The City does not demonstrate, in law or logic, that the need to deter drivers from exceeding the time permitted for parking—before they have even done so—is sufficient to justify a warrantless search.

I've never liked having my tires chalked. It's not quite Minority Report territory, but it's still invasive. I can only imagine how those with sports cars and expensive, glossy tires must feel about having their property marked-up (vandalized?) while they obey every law.

The appeals court ruling does not mean that cities have to stop closely monitoring properly parked vehicles, it only applies to the physical marking that goes with chalking a tire. Simply taking photos of vehicles could be an acceptable alternative in place of marking with chalk.

It is also possible that in some circumstances chalking a tire could be considered allowable in the interest of public safety. The appeals courts says that if a city can demonstrate that chalking a tire is necessary for public safety, then the chalking could be considered reasonable. It is the practice of routinely chalking without probable cause that the appeals court is ruling against.

While it is possible cities may choose to continue chalking tires under certain circumstances, it is more likely we will see most adopt another measure of monitoring vehicles to avoid possibly violating the Fourth Amendment.