United States v. Castillo, 28 F. Supp. 3d 673

Trooper Collins observed a white Ford Explorer driving in the left lane on U.S. 59 during early morning hours; a “Left Lane for Passing Only” sign stood about 5.3 miles behind where he first saw the Explorer.
Collins followed the Explorer for several miles (eventually coming behind it roughly 8 miles from the sign) and observed the driver keep the vehicle in the left lane despite twice pulling beside and then back to give an opportunity to change lanes.
Collins saw a passenger who averted her eyes and, after stopping the vehicle, discovered three people hidden on the floorboard; defendants Castillo (driver) and Gonzalez (front passenger) were charged with bringing in and harboring aliens.
Defendants moved to suppress, arguing the traffic stop violated the Fourth Amendment because Collins lacked reasonable suspicion that Castillo had violated the left-lane sign rule (they contended Collins had no basis to conclude the vehicle had passed the sign).
The court treated Texas law (Abney) as requiring that a driver have notice of a traffic-control device (i.e., the sign) within a reasonable distance for a violation to exist, making the critical question whether Collins had reasonable suspicion the Explorer had passed the sign.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether officer had reasonable suspicion to stop vehicle for violating a “Left Lane for Passing Only” sign	Officer (government) argued facts (distance from sign, limited entry points, continuous observation, and lane behavior) made it more likely than not the Explorer had passed the sign, giving reasonable suspicion to stop	Castillo/Gonzalez argued officer lacked reasonable suspicion because Collins did not see the Explorer pass the sign and the sign might be far enough away that the driver could have entered U.S. 59 after the sign	Court held officer had reasonable suspicion: probabilistic assessment favored that the Explorer had passed the sign given limited on-ramps/entrances in the 5.3-mile stretch and continuous observation, so stop did not violate Fourth Amendment

Abney v. State, 394 S.W.3d 542 (Tex. Crim. App. 2013) (state law requires notice of a traffic-control device within a reasonable distance for an offense based on that device)
United States v. Lopez-Moreno, 420 F.3d 420 (5th Cir. 2005) (traffic stop must be supported by objectively reasonable suspicion)
United States v. Arvizu, 534 U.S. 266 (2002) (reasonable-suspicion inquiry uses totality of the circumstances)
Navarette v. California, 134 S. Ct. 1683 (2014) (reiterating that reasonable suspicion is a low, probabilistic standard)
United States v. Garcia, 976 F. Supp. 2d 856 (N.D. Tex. 2013) (similar factual question; court found presence of multiple on-ramps undermined reasonable suspicion)
Whren v. United States, 517 U.S. 806 (1996) (selective enforcement concerns are Equal Protection, not Fourth Amendment)
Mouton v. State, 101 S.W.3d 686 (Tex. App.—Texarkana 2003) (approved as a fact-specific decision where sign proximity supported the stop)