Editing Traffic stop (section)

===Legal basis for stops===
In the United States, traffic stops have been criticized for their use in police [[dragnet (policing)|dragnets]] to check compliance with laws such as those requiring the use of seat belts or those prohibiting driving while impaired. Some people have objected that the tactic violates the [[United States Constitution]]; the [[Fourth Amendment to the United States Constitution|Fourth Amendment to the Constitution]], part of the [[United States Bill of Rights|Bill of Rights]], contains a provision against [[Fourth Amendment to the United States Constitution|unreasonable search and seizure]]. However, the [[United States Supreme Court]] has ruled that a motor vehicle is subject to a diminished expectation of privacy as compared to a home.  Reasons include the fact that motor vehicles are typically driven on public streets, that said vehicles are generally subject to public licensing and registration requirements, and that said vehicles are generally held out to public view in a way different than that of traditional dwellings.

*In ''[[Delaware v. 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 checkpoint]]s is constitutional. Under the [[Ninth Amendment to the United States Constitution|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 to the United States Constitution|Fourth Amendment]].