A traffic stop by an officer a seizure of the vehicle's occupants, necessarily implicating the Fourth Amendment's prohibition against unreasonable searches and seizures. Delaware v. Prouse, 440 U.S. 648, 653, 59 L. Ed. 2d 660, 99 S. Ct. 1391 (1979); State v. Atkinson, 128 Idaho 559, 561, 916 P.2d 1284, 1286 (Ct. App. 1996). Under the Fourth Amendment, an officer may stop a vehicle to investigate possible criminal behavior if there is articulable and reasonable suspicion that the vehicle is being driven contrary to traffic laws. United States v. Cortez, 449 U.S. 411, 417, 66 L. Ed. 2d 621, 101 S. Ct. 690 (1981); State v. Rawlings, 121 Idaho 930, 932, 829 P.2d 520, 522 (1992); State v. Flowers, 131 Idaho 205, 208, 953 P.2d 645, 648 (Ct. App. 1998). The reasonableness of the suspicion must be evaluated upon the totality of the circumstances at the time of the stop. State v. Naccarato, 126 Idaho 10, 12, 878 P.2d 184, 186 (Ct. App. 1994). The reasonable suspicion standard requires less than probable cause, but more than mere speculation or instinct on the part of the officer. Id.