Tougher DUI penalties and photo enforcement may have helped spur the nearly 18 percent decline in the number of highway-related deaths in Arizona last year, according to the Governor's Office of Highway Safety.

Arizona had 1,066 traffic fatalities in 2007, down from 1,293 in 2006, according to a report released last week by the National Highway Traffic Safety Administration.

Traffic deaths across the nation were the lowest in 13 years. Arizona ranked fifth for the highest percentage reduction in fatalities.

Deaths in all four categories of traffic-related fatalities - vehicles, pedestrians, motorcyclists and bicyclists - declined from 2006, according to the Arizona Department of Transportation.

The Office of Highway Safety credited a combination of factors, such as stiffer penalties for DUI and photo enforcement and a safer driving environment.

For example, public awareness of the harsher DUI penalties, which went into effect in September, may have spurred drivers to think more carefully about unsafe driving. A spokeswoman for AAA Arizona said that drivers may be developing better driving habits.

Other factors that have contributed to the decline in traffic-related deaths include:

• Safer vehicles. Newer vehicles tend to be safer, experts say, and with newer models on the road, drivers are less likely to be in a fatal accident.

 • A reduction in miles driven. Nationwide, Americans drove slightly less in 2007 than in 2006, partly due to higher gas prices.

Arizona could reduce traffic deaths even more if the state passed tougher legislation to require drivers to wear seat belts and increased the required age for booster seats. More than half of those killed in 2007 accidents were not wearing a seat belt, and about 45 percent would have survived had they worn a seat belt.

The Teenage Driver Safety Act, a law that went into effect July 1, requires more driver training, a curfew and other limitations on young drivers.

Even with the reduction in fatalities, the more than 1,000 deaths last year is a major issue.