An “expectation of privacy” is what protects citizens from searches and seizures from the State. Generally, if a citizen has a reasonable expectation of privacy, there must be some additional fact which would allow an officer to conduct a search or seizure upon that person.
One of such reasons may be that the person is operating a commercial vehicle.
A key U.S. Supreme Court decision on this subject is New York v. Burger (U.S. 1987). The court held that warrantless searches of closely regulated industries are constitutional if the rules governing the searches offer an adequate substitute for the 4th Amendment warrant requirement. To do that, the rules must do two things: Provide notice to owners that their property may be searched for a specific purpose and to “limit the discretion of the inspecting officers.”
Iowa courts have applied this thinking to searches without cause of commercial vehicles, noting that motor vehicles are pervasively regulated by statute, and that commercial vehicle drivers are on notice they could be stopped for inspection.
US v. Knight, (8th Cir. App. 2002) provides a little insight into how far searches of commercial vehicles can go. There, the defendant’s commercial vehicle was stopped and searched under the North American Standard Inspection Program, which allows officers to randomly stoop commercial vehicles for specific types of searches. The officer conducted an inspection which included rummaging through the defendant’s personal briefcase. This search was determined to be unconstitutional.
Therefore, commercial drivers have a lowered expectation of privacy because they are in a highly regulated industry. The State has the right to determine if the drivers are in compliance with all regulations. But, as Knight points out, the right to search commercial vehicles is not without limits.