According to Arizona Revised Statutes 28-903, the practice of lane splitting is illegal in the state of Arizona. The law specifically states that motorcyclists may not operate a motorcycle between two adjacent rows of vehicles or two lanes of traffic.

Lane splitting is performed by motorcyclists due to the fact that their vehicles are smaller all the way around than standard passenger vehicles and light trucks. Bikers often feel it is a safer maneuver to lane split than stay confined to one lane of backed up or stopped traffic. By engaging in this maneuver, they often feel they can avoid accidentally getting bumped from behind in slow-moving traffic and also remain more visible to drivers.

It also enables motorcycle drivers to bypass a significant amount of backed up traffic which increases the flow of traffic and keeps the exposed motorcyclists from having to bask in Arizona’s harsh heat. 

Arizona legislators in 2010 passed a bill that would have allowed a one-year lane-splitting pilot program, but it was vetoed by then-Gov. Jan Brewer, a Republican. She cited concerns about its impact on safety and whether motorists would have enough time to be educated properly about the changes. Link of veto: https://www.azleg.gov/govlettr/49leg/2R/HB2475.pdf  

For a state that doesn’t require riders to wear helmets I can’t seem to grasp the idea that they are afraid to let riders lane split under similar guidelines as California; Riding on the shoulder of a road or freeway is illegal. It is not considered lane splitting. Don’t share lanes next to large vehicles such as semi-trucks or motorhomes. Also, don’t split lanes if the condition of the road makes it dangerous. Take into consideration the width of the lanes, the weather, and the lighting conditions.

Guidelines for motorcyclists:

Travel at a speed that is no more than 10 MPH faster than other traffic – danger increases at higher speed differentials.
It is not advisable to lane split when traffic flow is at 30 mph or faster – danger increases as overall speed increases.
Avoid splitting in lanes near freeway on-ramps and exits.

Guidelines for motorists:

Motorists should not take it upon themselves to discourage motorcyclists from lane splitting.
Intentionally blocking or impeding a motorcyclist in a way that could cause harm to the rider is illegal.
Opening a vehicle door to impede a motorcycle is illegal.

Studies have shown that lane splitting is actually a safe way to drive and can reduce traffic and road accidents when done correctly. That Being said, motorcyclists who lane split at high speeds and in unsafe conditions are in greater danger. It’s important that all who use the road know and understand the safe implementation of sharing lanes. So as long as motorcyclists and motorists respect the privilege of having the freedom to lane split then it would only be beneficial rather than dangerous.