Chalking a tire to determine how long a car has been parked was ruled to be a search in violation of the Fourth Amendment. The Sixth Circuit in Michigan ruled that a search occurs when the government: (1) trespasses upon a constitutionally protected area, (2) to obtain information.
Chalking a tire constituted a common law trespass because parking enforcement officers made intentional physical contact with the property of another when it placed a chalk mark on the tire. This intrusion, though minimal and not resulting in damage, was a trespass nonetheless.
Furthermore, the trespass was “conjoined with . . . an attempt to find something or to obtain information” in that the purpose of the chalk marks was to identify vehicles which had been parked in the same location for a certain period of time. That information is then used by the City to issue citations.
Not all warrantless searches are unconstitutional, only unreasonable searches. The court ruled that the vehicles were parked legally, there was no probable cause probable cause to believe that the vehicle contained evidence of a crime” or even an “individualized suspicion of wrongdoing.” Consequently, the automobile exception did not apply nor was there a reduced expectation of privacy.
The Community Caretaker exception to the warrant requirement also was inapplicable since the purpose of chalking is to raise revenue, and not to mitigate public hazard and no injury or ongoing harm to the community at large would result by a lawfully parked vehicle in a proper parking location.
So if you are lawfully parked but exceeding the allotted time on the sign, the parking enforcement cannot chalk your tires to determine whether you have exceeded the prescribed time. If they do, challenge it as an unconstitutional search and cite Taylor v. City of Saginaw (US Court of Appeals, Sixth Circuit, 4/22/2019)