Rider magazine predicted that "issues are almost certain" due to the law's ambiguity as to what is and is not legal. Cycle World said that while it, "is a step in the right direction, the AB 51 Bill doesn't actually do much to clear anything up." Effective January 1, 2017, section 21658.1 was added to the California Vehicle Code and defines lane splitting, which is now explicitly legal in California. The California Highway Patrol released new lane splitting safety tips as of September 27, 2018. Bills to legalize lane splitting have been introduced in state legislatures around the United States over the last twenty years but none had been enacted before California. Utah legalized lane filtering in 2019 and went into effect on May 14, 2019. The Utah Department of Public Safety Highway Safety Office created infographics and videos that demonstrated safe and legal lane filtering. Montana's governor signed SB9, legalizing lane filtering in March of 2021 and the bill went into effect on October 1, 2021. This law permits filtering at up to between vehicles that are stopped or moving at up to . Arizona's governor signed SB1273 on March 23rd, 2022 and it will go into effect after 90 days after the end of the second regular session of the 55th Arizona State Legislature. This legislation mirrored Utah's bill, permitting motorcycles to travel at up to between completely stopped vehicles on roads with a speed limit of or slower and at least two adjacent lanes in the same direction of travel, as long as the movement could be made safely. Senator Tyler Pace sponsored the bill and Representative Frank Carroll (Arizona politician) co-sponsored it, and the bill received support from ABATE of Arizona, a state motorcyclists' rights organization. See also Motorcycle lane Notes References Further reading All available from the United Kingdom Department of Transport websites (executive summary), and the Transportation Research Board Record publication: WSP Policy and Research UK, Motorcycles and congestion: the effect of modal shift: Phase 3 policy testing. 2004, WSP for Uk Department for Transport: Cambridge UK. p. 44. WSP Policy and Research UK, Motorcycles and congestion: the effect of modal shift: Phase 2 – Modelling Methodology. 2004, WSP for Uk Department for Transport: Cambridge UK. p. 47. WSP Policy and Research UK, et al., Motorcycles and congestion: the effect of modal shift: Summary Final Report. 2004, WSP for Uk Department for Transport: Cambridge