With the recent release of its "Ten Commandments" for drivers, the Vatican offered its solution to a problem that has vexed state policymakers and traffic-safety experts for more than a decade.
Aggressive driving and its more violent cousin, road rage, first plowed their way into the public consciousness in the 1990s with stories of drivers running fellow motorists off the road or gunning them down in a fury. Since then, experts have been unable to reach a consensus on how best to deal with the dangers of run-amok motorists.
While the Roman Catholic Church appealed to morals to tame what it called drivers' "primitive" behavior, states are torn between more conventional tools at hand - legislation and enforcement.
Some states have pushed to write new aggressive driving statutes or to strengthen existing traffic laws, while proponents of a different school of thought have advocated beefing up enforcement instead.
Neither course is without problems. New laws tend to create unnecessarily complex traffic codes that do little more than ensure defense attorneys have plenty of work, opponents say. But adding traffic cops or highway patrol troopers is expensive, and many police forces are already stretched thin.
In 2006 and 2007, at least nine state legislatures considered bills related to aggressive driving. Two of them - California and Indiana - enacted new laws, joining 10 states that already had statutes creating the new, distinct violation of aggressive driving, according to the National Conference of State Legislatures. Aggressive drivers could face jail time in seven states: Arizona, Delaware, Georgia, Indiana, Nevada, North Carolina and Virginia. The other states with aggressive driving statutes are Florida, Maryland and Rhode Island.
Aggressive driving usually is defined as a series of multiple violations, such as tailgating, speeding and improperly changing lanes, that endanger people or property. No state yet has specifically outlawed road rage, which the National Highway Traffic Safety Administration defines as an intentional, violent act usually meant to injure or kill another driver.
Arizona was first in the nation to pass a criminal aggressive driving statute, beginning an enforcement program in 1999. The state has benefited from having a law on the books, said Harold Sanders, a spokesman for the Arizona Department of Public Safety.
Statistics indicate there are fewer collisions, fewer driver confrontations and fewer citizen complaints in areas patrolled by one of the state's aggressive driving enforcement units, he said.
But on a broader scale, it is unclear whether state statutes have had a significant effect. A 2004 study of five states with aggressive driving statutes by the National Center for State Courts found that laws in Maryland, Nevada, Rhode Island and Virginia were rarely used. Florida's saw more use, but it carries no penalties and is used only for statistical purposes.
Instead, these states generally relied much more on reckless driving statutes, which often carry harsher penalties or are easier to prove, the report said.
Meanwhile, some states without aggressive driving statutes have enforcement programs. Washington state has no formal law, but its highway patrol has a special unit called the Aggressive Driving Apprehension Team that uses unmarked cars to patrol for aggressive drivers. Motorists are cited for specific moving violations, but officers also record what they believe are instances of aggressive driving for statistical purposes. The number of aggressive drivers counted by officers increased yearly - from 27,306 in 2002 to 58,993 in 2006.
State patrol spokeswoman Melissa Van Gorkom said an aggressive driving statute likely would not have a significant effect.
Barbara Harsha, executive director of the Governors Highway Safety Association, said many states wouldn't have the resources to enforce a new aggressive driving statute. "The real issue here is that law enforcement resources across the country have been reduced. Law enforcement officials have been pulled off to work homeland security. There are high retirement numbers," she said.
For the most part, the federal government has left states to handle aggressive driving. The National Highway Traffic Safety Administration convened a task force that in 2001 issued the National Aggressive Driving Action Guide . The guide recommended that states create aggressive driving statutes or strengthen existing aggressive or reckless driving statutes.
But John Archer, chairman of the National Committee on Uniform Traffic Laws and Ordinances, categorically rejects aggressive driving laws.
"There is a lot of anger about so-called aggressive drivers. The question is whether having a law will make it better, and I don't think it will. By putting an aggressive driving statute on the book, what you're really doing is making it easier for defense lawyers to make a lot of money" because the offense is complicated to prove, said Archer, who has previously advised the NHTSA.
Leon James, a researcher in Hawaii who has studied aggressive driving and road rage for 20 years and has become known as "Dr. Driving," has concluded - like the Vatican - that changing drivers' hearts and minds is key. He advocates an extensive education campaign.
"Aggressive driving is a cultural norm," James said. "We need to retrain our traffic emotions. Laws can help, but they cannot solve the problem."