Can Police Stop You for Driving in the Middle Lane in Arizona?

Yes — under a November 28, 2025 ruling from the Arizona Supreme Court, an officer can lawfully stop you for staying in the middle lane on a Maricopa County freeway if you are driving slower than the flow of traffic and another vehicle passes you on the right. The decision in State v. Alvarez-Soto expands what officers can use as reasonable suspicion for a traffic stop — and that has direct consequences for any DUI, drug, or weapons case that starts with one. The Law Office of James E. Novak handles Fourth Amendment challenges in Tempe, Mesa, Chandler, Gilbert, Scottsdale, and Phoenix criminal cases every week, and this ruling changes how those motions are litigated.

What Did the Arizona Supreme Court Decide in State v. Alvarez-Soto?

On November 28, 2025, the Arizona Supreme Court issued a unanimous opinion reinstating a marijuana trafficking conviction out of Pinal County. The case began in December 2018 when a Department of Public Safety trooper observed a vehicle traveling in the middle lane of Interstate 10 at three miles per hour over the 75 mph limit, then slowing to 70 mph as another car passed on the right.

The trooper stopped the driver under A.R.S. § 28-721(B), Arizona’s “stay right” law, which requires drivers moving slower than the normal speed of traffic to use the right-hand lane. After a canine sniff and consent search, officers recovered 55 pounds of marijuana from the trunk. The driver moved to suppress the evidence, arguing the stop was unconstitutional.

The Arizona Court of Appeals agreed with the driver in 2024, calling the trooper’s interpretation of the stay-right law overly aggressive. The Supreme Court reversed. Writing for the unanimous court, Justice John Lopez held that the trooper had the “minimal reasonable suspicion” required under the Fourth Amendment to justify the stop. James Novak’s background as a former Maricopa County prosecutor gives him a working understanding of exactly how state troopers and local officers are now being trained to apply this expanded authority on Maricopa County highways.

What Is Arizona’s “Stay Right” Law Under A.R.S. § 28-721(B)?

A.R.S. § 28-721(B) requires that a driver moving at less than the normal speed of traffic — under the conditions then existing — drive in the right-hand lane available for traffic, or as close as practicable to the right-hand curb or edge of the roadway. The statute carves out exceptions for passing, preparing to turn left, and avoiding obstructions.

The key phrase is “normal speed of traffic.” That is not the posted speed limit — it is the speed of the cars actually on the road at that moment. Under Alvarez-Soto, an officer can use a single vehicle passing you on the right as evidence that you are below that prevailing speed and therefore in violation of the statute. The violation does not require dangerous driving, weaving, or aggressive maneuvers. It is a lane-position offense, and after this ruling, it is now one of the easiest pretexts for a stop on Arizona freeways.

How Does This Ruling Affect DUI, Drug, and Criminal Cases in Maricopa County?

Most felony drug cases in Maricopa County — and a significant share of DUI cases — begin with a traffic stop. The stop is the gateway. If the stop is illegal, everything that follows can be suppressed under the exclusionary rule: the officer’s observations, the field sobriety tests, the breath or blood results, the canine alert, and any contraband recovered from the vehicle.

Before Alvarez-Soto, defense attorneys could argue that a stay-right stop required something more than slower-than-traffic driving. After Alvarez-Soto, that argument is significantly harder. Officers patrolling I-10, US-60, Loop 101, Loop 202, and I-17 can now point to a single passing vehicle as articulable evidence of a § 28-721(B) violation. If you are facing charges in Tempe, Mesa, Chandler, Gilbert, Scottsdale, or Phoenix after a freeway stop, the suppression analysis in your case just changed.

What Defenses Still Work After Alvarez-Soto?

The ruling does not eliminate Fourth Amendment defenses to traffic-stop cases. It narrows one specific argument. Several defense angles remain viable:

• Pretextual stop with unlawful extension. Even a valid initial stop becomes unconstitutional if the officer extends it beyond the time needed to address the traffic infraction without independent reasonable suspicion of another crime. The Supreme Court in Alvarez-Soto declined to address this argument and remanded it for further review.
• Lack of articulable facts. The officer must testify to specific observations — speed, lane position, passing vehicles — not generalized hunches. Vague or inconsistent testimony can still defeat a stop.
• Invalid consent to search. Consent to a canine sniff or vehicle search must be voluntary. Coercion, prolonged detention, or misrepresentation by the officer can invalidate it.
• Canine reliability challenges. Drug-detection dogs are not infallible. Training records, certification, and false-alert history are all fair game for a defense attorney with the technical background to review them.
• Bodycam and dashcam analysis. Video evidence often contradicts an officer’s report. The Supreme Court in Alvarez-Soto emphasized that trial courts retain primary authority over factual findings from video — which means a thorough suppression hearing is more important than ever.

Frequently Asked Questions

Is driving in the middle lane illegal in Arizona?

Not on its own. Under A.R.S. § 28-721(B), it becomes a traffic violation only when a driver is moving slower than the normal speed of traffic and fails to move to the right lane. After State v. Alvarez-Soto, being passed on the right by another vehicle is enough to trigger reasonable suspicion of that violation.

Can the officer search my car after a stay-right stop?

Not automatically. The officer needs your consent, a warrant, probable cause, or a recognized exception such as a positive canine alert. If consent was not voluntary or the stop was unlawfully extended, the search and any evidence can be challenged.

What should I do if I was stopped on a Maricopa County freeway?

Do not volunteer information beyond your license, registration, and proof of insurance. Decline consent to a vehicle search politely and clearly. Do not answer questions about where you have been or what you are carrying. Then contact a Maricopa County criminal defense attorney before your first court date.

Speak with a Maricopa County Criminal Defense Attorney

If you were stopped on I-10, US-60, Loop 101, Loop 202, or any Maricopa County roadway and the stop led to DUI, drug, or weapons charges, the Alvarez-Soto ruling does not end your defense — but it changes how it must be litigated. James Novak is a former Maricopa County prosecutor with the technical training needed to pick apart Fourth Amendment suppression issues — the details of the stop, the officer’s testimony, and the evidence that follows.

Call (480) 413-1499 or contact The Law Office of James E. Novak online for a free initial consultation. Available 24/7. Flat affordable fees, no hidden costs.