Iowa had the lowest percentage of speed-related fatality traffic crashes in the nation in 2008, a federal report shows.

Iowa recorded 412 fatalities, with 41 of those involving speeding in 2008, according to the National Highway Traffic Safety Administration. That's slightly less than 10 percent of all motor vehicle deaths.

Arkansas was second at 10.5 percent and New Jersey was third at 11 percent.

Nationwide, 11,674 of 37,261 fatalities involved speed, or 31 percent.

Iowa traffic investigators determine a fatal crash was speed-related if the motorists involved were driving faster than the posted speed limit or too fast for existing conditions.

One factor behind Iowa's low ranking could be demographics, said Robert Thompson, an official with the Iowa Governor's Traffic Safety Bureau. Iowa has a large population of older drivers who typically don't drive too fast, he said.

Iowa ranks fifth nationally in its percentage of people age 65 and older. In 54 of Iowa's 99 counties, at least 20 percent of licensed drivers are in the 65-and-older age group.

Col. Patrick Hoye, chief of the Iowa State Patrol, credited a strong statewide traffic enforcement effort by state troopers, city police departments and sheriff's offices. Their anti-speed campaign "has paid big dividends," he said.

During 2009, Iowa had 373 traffic fatalities, the fewest since World War II.