Prouse, 440 U.S. 648 (1979), the U.S. Supreme Court ruled that the police stopping vehicles for no reason other than to check the drivers' licenses and registrations was unconstitutional. In New York v. Belton, 453 U.S. 454 (1981), the U.S. Supreme Court ruled that when a police officer has made a lawful arrest of a driver, he may search the passenger area of the vehicle without obtaining a warrant. Recent Court decisions have limited the scope of the search even further. In Michigan Dept. of State Police v. Sitz, 496 U.S. 444 (1990), the U.S. Supreme Court ruled that the use of sobriety checkpoints is constitutional. Under the Ninth Amendment to the U.S. Constitution, states have the right to reasonably regulate the safety, health, and welfare of their citizens. In Illinois v. Caballes, 543 U.S. 405 (2005), the U.S. Supreme Court held that a dog sniff, conducted during a concededly lawful traffic stop that reveals no information other than the location of a substance that no individual has any right to possess, does not violate the Fourth Amendment. In Arizona v. Gant, (2008), the U.S. Supreme Court ruled that an officer must demonstrate a threat to their safety or a need to preserve evidence related to the crime of arrest in order to search a vehicle pursuant to an arrest, distinguishing New York v. Belton. In Rodriguez v. United States (2015), a case originating in federal court, the Supreme Court declared that the protraction of a traffic stop with the intent to use a sniffer dog to search for evidence for which no reasonable suspicion exists is violative of the Fourth Amendment. See also Traffic ticket Traffic police Highway patrol State police Traffic warden Consent search Car chase Motor vehicle exception References Further reading External links Narcotics searches in traffic stops OK – Jerry Seper, The Washington Times (January 25, 2005) Police Behavior during Traffic and Street Stops Bureau of Justice Statistics Traffic Stop Data Reports Texas Department of Public Safety Law enforcement Law enforcement in the United States Law enforcement techniques Searches and seizures Traffic law