Arizona House Bill 2475 would make it legal for motorcyclists to split lanes in Maricopa county. The catch? It’s only for one year (2011) and only applies during stopped traffic. It’s interesting progress nonetheless and will undoubtedly spark its own controversy (just check out the comments in the source article). What’s also noteworthy is that if the bill is passed, it will be the first time a state has explicitly allowed lane splitting. California has always tolerated it, but there are no laws specifically allowing or disallowing the practice.
Source: ABC15.com
Update: the bill was vetoed by the governor.
http://www.azleg.gov/FormatDocument.asp?inDoc=/legtext/49leg/2r/bills/hb2475o.asp