Driving in Arizona

HOV Lane in Phoenix

TripSavvy / Judy Hedding

When it comes to seeing the natural beauty of Arizona, there's no better way to take in the scenery than driving across the state.

However, keep in mind that some driving laws and customs in Arizona are different from those elsewhere in the United States. From knowing the right speed to drive along the winding roads overlooking the Grand Canyon to understanding the right of way on the congested streets of downtown Phoenix, it's important to brush up on your knowledge of Arizona's driving laws before you set out on the road.

Rules of the Road

While similar to the rest of the United States, there are several customs, traditions, and even laws regarding driving in Arizona that are quite different from what you may be used to back home. From a zero-tolerance policy on driving while under the influence to city-specific ordinances on cell phone usage, it's important to understand the basic rules of the road in Arizona before you start driving there.

  • Children: While every state has its own laws about car and booster seats for children, Arizona's are based on age and height rather than weight. Children ages 5 through 7 (younger than 8) and 4-foot, 9-inches or shorter must ride in a vehicle in a booster seat while children under the age of 5 must ride in a car seat.
  • Alcohol: In Arizona, no amount of alcohol is exempt from driving under the influence (DUI) laws. While you are certain to be fined or incarcerated for blood-alcohol readings of 0.08 percent or higher (the statewide limit), you can be cited at any level if a police officer believes you are impaired.
  • License plates: Rental car companies know this, but, if you are moving here or visiting with your own vehicle, you might not know that you can be cited if you have a license plate holder that covers up the name of the state on the plate. A police officer may not stop you for that, but it might be added as an additional offense if you are stopped for any other reason.
  • Roundabouts: Travel circles and roundabouts are becoming popular in Arizona, especially on less-traveled streets and in smaller cities and towns. Cities are finding they are cheaper than traffic lights, keep traffic moving, and, if there are fender benders, they tend to be much less serious with drivers traveling at slower speeds. In Sedona alone, there are over 11 roundabouts.
  • Cell phones: In April 2019, Arizona became the 48th state to ban the use of cellular devices while operating a motor vehicle. However, some use of hands-free devices is allowed under the law, which set a grace period until January 2021 before fines would be issued.
  • Distracted driving: The distracted-driving law in Arizona pertains to speeding violations. An officer may write a citation to a driver for certain things including eating, shaving, applying make-up, and putting ketchup on a burger, if that driver is speeding while doing so.
  • Motorcycle helmets: Arizona does not have a law requiring motorcyclists to wear helmets if they are over 18 years of age, but drivers 18 and younger must wear one.
  • Move Over Law: If you see emergency vehicles on the side of the road, you must give them ample space by moving over one lane if it is not dangerous to do so. If you cannot move over safely, you must reduce your speed at least 10 miles under the speed limit as you pass the emergency vehicle.
  • Tolls: Arizona doesn't have highway tolls. There are no monthly highway passes, tickets to punch, or extra charges from rental car companies for using toll roads since there are no toll roads. That’s not to say the issue doesn’t come up nearly every year. After all, maintaining roads and highways is expensive, and budgets are always tight.
  • In case of an emergency: The Arizona state government offers Roadside Motorist Assistance (RMA) through the Arizona Department of Public Safety. Call 911 if you've been in a car accident or need assistance immediately. AAA and other roadside assistance programs (private) are also available across the state.
  • Stupid Motorist Law: Arizona has a law that punishes motorists who drive their vehicle into an area known to be flooded and then require emergency assistance.

Weather and Road Conditions in Arizona

Weather plays a role in safe driving no matter where you come from. While the state rarely has natural disasters like hurricanes or tornadoes, it does have a weather phenomenon known as the monsoon season, which typically arrives in the summer and occasionally brings heavy rain, heavy winds, and dust storms that make visibility impossible.

When the rains come, don't drive into those areas that are designated by signage as being dangerous when flooded. Heavy and fast water comes rushing down normally dry washes. Every year some people have to be rescued because they thought they could drive through standing water only to have to be airlifted from the roofs of their vehicles. Plus, Arizona’s Stupid Motorist Law means you could be responsible for the cost of your rescue if you've ignored signs and posted warnings.

Getting an Arizona Driver's License

As with all of the United States, any state-issued driver's license is valid in Arizona for operating a motor vehicle or identifying oneself at a government agency. However, if you are moving to Arizona, you should know there is no "grace period" for obtaining an Arizona driver's license and registering your vehicle in the state, and that doesn't only apply to people who have completely relocated.

If you pay the equivalent of resident tuition, have a job in state that's not a seasonal agricultural position, have kids in school, have a business, or spend seven months or more in the state without paying nonresident tuition at a school, you are considered a resident and are expected to register your car and obtain an Arizona driver's license. However, it's important to note the definition of "resident" applies only to motor vehicle services.

Speed Limits and Safety Corridors

When it comes to getting around Arizona, the major interstate highways may be the fastest option, but the state roads are far more scenic. Whichever way you choose to travel, though, you should be aware of the laws governing the use of these roadways first.

The standard speed limit on main interstates in Arizona is usually either 55 or 65 miles per hour (mph) as the roads pass through major cities and 75 mph between major cities. Of course, there are exceptions. On a highway that does not have work zones or other special lower speed limits posted, an unwritten rule is that if you drive no more than 9 mph over the speed limit (and not driving erratically) you probably won’t be stopped.

However, in December 2016, the Arizona Department of Transportation began designating Safety Corridors, segments of both urban and rural highways where serious traffic accidents seem more likely to occur. In a Safety Corridor, enforcement will be aggressive, and drivers may be ticketed for speeding and any other violations with zero tolerance, even if going only 1 mph over the speed limit.

You will find these Safety Corridors on I-10, I-40, and US60. Signage indicates where the zero tolerance areas begin and end. Certainly, if you are stopped for some other reason outside of a Safety Corridor, the officer might tack on a speeding violation, even if you're driving less than 10 mph over the speed limit.

Interstate 10: East-to-West and North-to-South

There is one aspect to driving in Arizona that can be confusing relative to Interstate 10, an interstate highway that generally runs east to west across the country. However, in Central Arizona, between Phoenix and Tucson, the I-10 is a north to south-bound road, which means that you will see highway signs directing you to I-10 East or I-10 West, even though you are driving north or south.

If you are driving south from Phoenix to Tucson, you will take I-10 East. If you are driving north from Chandler to Phoenix, you will take I-10 West. The Interstate eventually does travel west again outside Downtown Phoenix as it moves on to Western Arizona communities and California.

Carpool and High Occupancy Vehicle Lanes

Major highways in Arizona—especially in and near major cities—have high occupancy vehicle (HOV) lanes, which are designated for cars with two or more total passengers (including the driver). There are certain hours when anyone can drive in those lanes and other hours when they are restricted. The fine is steep if you are stopped for driving in an HOV lane when you shouldn’t.

Additionally, the lines on the highways as they relate to the HOV lanes can be confusing. It is a rule of thumb everywhere else that you are not supposed to change lanes over a solid white lane, but the HOV lane in Arizona is an exception. You may enter or leave the lane at any time; ignore the solid line. In fact, according to ADOT, the double solid white lines also mean nothing. They are just spacers with no associated additional regulations.

HOV lanes do have exits; however, you are not permitted to use an HOV exit unless you are legally entitled to use the HOV lanes. Finally, if your car is a hybrid or other special vehicle, you still can’t use the HOV lane without another person riding with you unless you have a special environmental plate or placard from Arizona MVD.

Navigating Phoenix

There are three major issues that most tourists face when driving in downtown Phoenix: troubles understanding where the METRO Light Rail runs, problems navigating the exits along the 202 Loop, and navigating the "suicide lanes" on 7th Avenue.

  • Someone who is not familiar with the streets of Downtown Phoenix can be easily confused, not only by the one-way streets and street restrictions but also by trying to avoid turning into the tracks. If you don’t have to drive into downtown Phoenix, try actually riding the METRO Light Rail instead.
  • Known as the Red Mountain Freeway in Phoenix and the Santan Freeway in the East Valley, the 202 Loop is actually not a complete loop; it's just three sides of an oval. When you are driving on a north-to-south highway like I-10 or SR101, you will cross over the Loop 202 twice, once over the northern part of the oval (Red Mountain) and once over the southern part of the oval (Santan). If someone tells you to “exit at the 202” make sure you know which 202 to take.
  • As in any city, rush hour in Phoenix is no treat, but there is an added wrinkle you should be aware if you are driving north or south on 7th Avenue (McDowell Road to Northern Avenue) or on 7th Street (McDowell Road to Dunlap Avenue): they are reversible lanes. Not-so-fondly referred to as “suicide lanes,” the intention is to use the center turning lane for southbound traffic during the morning commute and for northbound traffic during the evening commute. Since you can’t make left turns at major intersections during these designated times, traffic in these lanes often slows for people turning left onto residential streets, or for people who just forgot, didn’t check the time, or don’t know they can’t make turns coming from the non-rush-hour side. Our advice is to stay out of not only the suicide lane but also the left lane to avoid cars swerving into it from the suicide lane.

Smoking in Cars With Kids

Although legislation has been proposed numerous times for a statewide ban on smoking in the car while children are present, only a handful of states across the country have done so thus far. However, the City of Tempe has a law that prohibits anyone from smoking in a vehicle with a person under 18 years of age in the vehicle.

While they say they won’t stop you just for that, they may cite you under the "no smoking around kids" rule if you get stopped for some other reason. Be aware that most of the cities and towns in the metro Phoenix area are adjacent, with little notice of when you're leaving one and entering another. It may just be safer to not smoke with the kids in the car at all in Arizona.