Lane splitting is currently illegal in Arizona, although a new lane filtering law has created a confusing situation. As a motorcyclist, you can’t go in between cars when traffic is in motion. However, you can lane filter, which is going in between cars and lanes when traffic is at a complete stop at a stop light.
Signed into law in March 2022, lane filtering is designed to keep motorcyclists safe by keeping them from being rear-ended while at a stop light. Note that lane filtering is only legal on roads with a speed limit of 45 mph or less and that you can only travel at 15 mph when going between other vehicles.