Enlarge By John Burgess, AP Officers investigate a fatal motorcycle accident Monday on Hwy 101 in Santa Rosa, Calif. The NTSB is urging states to make helmets mandatory for all riders. MOTORCYCLIST DEATHS BY YEAR MOTORCYCLIST DEATHS BY YEAR NTSB pushes for stricter motorcycle helmet laws The National Transportation Safety Board , the independent federal agency charged with determining the probable cause of transportation accidents and promoting safety, is urging states to enact mandatory helmet laws for all motorcycle riders. More than 12 motorcyclists die in crashes in the USA each day, and the leading cause of death in those fatalities is head injuries, NTSB Vice Chairman Christopher Hart said Tuesday in urging states without laws covering all riders to adopt them. Currently, 47 states and the District of Columbia have motorcycle helmet laws. STUDY: Sleepiness a factor in 17% of road deaths TRAFFIC DEATHS DOWN: But not low enough However, only 20 states and the District require them for all riders; the other 27 states require helmets only for some riders, usually those under 18, according to the Governors Highway Safety Association, which has studied helmet use extensively. Three states — Illinois, Iowa and New Hampshire — have no helmet law. Motorcycles comprise just 3% of vehicles on the nation's road but are involved in 13% of fatalities, Hart said. He said helmets that meet federal Department of Transportation regulations are 37% effective in preventing motorcycle fatalities. He said the "novelty helmets" preferred by some riders have less padding against impact and penetration, and are more easily lost in crashes. For years, motorcycle deaths have climbed steadily even as nearly every other category of traffic fatality has declined. However, last year for the first time in 11 years, motorcycle fatalities dropped — a decline that some experts attribute to the economy. Motorcycle enthusiasts aren't welcoming NTSB's effort. "It's a little alarming and a little disturbing that they would pursue motorcycle helmet laws after an 11-year, record-breaking motorcycle death drop," said Jeff Hennie, vice president of the Washington, D.C.-based Motorcycle Riders Foundation, which has over 250,000 members. "We're making so much progress in the areas of rider education and motorist awareness, to call on the states to adopt motorcycle helmet laws, it seems like a jump in the wrong direction," Hennie said. The trend in recent years has been for states to repeal universal helmet laws, said Jonathan Adkins spokesman for the Governors Highway Safety Association. "The NTSB is extremely well thought-of and very credible," Adkins said. "The fact that they're weighing in on this issue is very helpful, and frankly, very brave. They will take some heat for it. There's really been no positive movement. But there's no argument that motorcycle helmet laws will reduce fatalities." Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more