Motorcyclists To Ride In Support Of Landmark High Court Challenge To ACC Levy SystemPhoto/Supplied. The judicial review alleges that ACC's current motorcycle levy structure relies heavily on engine capacity as a pricing factor despite serious questions over whether engine size is a valid measure of crash risk. Advertisement - scroll to continue readingMAGNZ also questions why previous vehicle safety incentives for cars have disappeared while motorcyclists have been subjected to increasingly steep levy increases. An Election IssueWith a General Election approaching, MAGNZ is calling on every political party to state its policy on motorcycle ACC levies. Tohu also says that representatives from ACT and Labour have agreed to meet to discuss possible improvements to the motorcycle levy system.