"The thing I notice is that drivers here are really nice, but it seems like they've got their heads in the clouds sometimes. They're not always aware of what's going on around them," said Anna Simmons, a recent Massachusetts college graduate spending the summer in Honolulu.

"In some instances, driving with aloha does have its limitations," agreed Sgt. Robert Lung of the Honolulu Police Department. "Sometimes it just makes more of a jam for everyone else."

By several indicators, Hawai'i drivers are among the least aggressive in the country. Hawai'i accident rates have been dropping steadily for years. One national study found that Hawai'i ranks 47th in the nation when it comes to making insurance claims for personal injury. In another survey, Hawai'i residents asked to evaluate their own behavior ranked themselves as the second least aggressive drivers in the United States and Canada.

"People can be courteous to a fault," said Rod Haraga, director of the state Transportation Department, which is developing an educational video to teach drivers about such basics as how to merge, change lanes and use turn signals.

Others, though, believe the state's declining accident rates are the result of careful driving that needs to be enhanced and encouraged.

"I see a lot of people cutting in front of you, changing lanes, and tailgating," said Kirk Beaver, a 33-year-old Salt Lake resident. "I'd rather see people get where they're going safely without any more aggression than we already have."

Among the topics that local drivers love to praise and complain about:

• A tendency to drive slower when it rains. University of Hawai'i engineering professor Panos Prevedouros said work he and graduate student Lin Zhang have done shows that local drivers reduce their speed an average of 6.1 mph when it's raining, far more than their counterparts on the Mainland.

"Actually, the right thing to do is maintain your speed and leave more distance" between your car and the car in front of you, Prevedouros said.

• Allowing cars to make a left turn in front of you, even if it means backing up traffic.

"You stop to be nice, but then all of the cars in back of you have to stop and wait there, too," Lung said. "It's a nice thing to do, but sometimes you have to consider what's happening behind you."

• Staying in the left lane of a highway or freeway while traveling at the speed limit or just below it. Although it's not illegal, a better or safer option might be to move over to the right lane whenever possible, allowing more aggressive drivers to pass, several professionals said.

"Nobody ever wants to drive behind a bus," said Larry Zablan, a tour bus driver for Roberts Hawai'i for 35 years. "Everybody will try to pass a bus even when we're doing the speed limit at 4 in the morning. The only way we don't get cut off by cars is if we follow a garbage truck."

• Merging improperly. Some drivers on a highway on-ramp come to a complete stop rather than accelerating in traffic. Some drivers on the highway slow when approaching a merge, causing traffic to back up behind them.

All of those behaviors can contribute to growing frustration and an increasingly aggressive response among drivers who normally consider themselves well-behaved.

"Everybody has their good and bad days," said Edwina Low, who commutes between Hawai'i Kai and Iwilei every day. "I try to be good on the road for my own safety but get frustrated sometimes when you see other people not paying attention."

University of Hawai'i psychology professor Leon James, who specializes in the study of driving behavior, has found that Hawai'i drivers consistently rate themselves as more passive than their counterparts on the Mainland and Canada.

Asked about such things as their own aggressiveness, degree of stress, the number of times they yell, honk their horns or make a rude gesture or in any way use their auto to punish others on the road, local drivers generally rank below the national average.

Overall, James' Web site (drdriving.org) puts Hawai'i drivers as No. 2 on the list of least-aggressive states and provinces.

The good news is that such driving behavior, along with other factors like slower driving conditions and tougher traffic laws, may contribute to a sharp reduction in accident rates and insurance claims in the state.

Despite having more cars on the road, state statistics show the overall number of reported accidents in Hawai'i has dropped from a high of almost 27,000 in 1989 to under 11,000 in 2001, the most recent year in which figures are available.

By far, the biggest causes of accidents are inattention and misjudgment, not aggressive driving behavior such as speeding and ignoring traffic signals, the statistics show.

However, some people think incivility is on the rise.

"Twenty years ago, you didn't see the aggressive, high-risk, rude and angry behavior that is increasing," said Loralei Brown, a driving instructor on O'ahu.

Brown said she often sees drivers responding with yelling or rude gestures to her student drivers who are trying to obey the speed limit.

"Obviously, driving at 23 mph in a 25-mph zone is a reasonable thing to do," she said. "However, the majority of drivers don't travel at the posted limit, and as they approach from behind they become quite impatient, looking for the first opportunity to pass."

Ryan Kaminaka, a 26-year-old Kailua resident, thinks the new behavior is generational.

"Mostly, it's the younger drivers who are acting more aggressive now," said Kaminaka, who admitted that his own behavior varies from day to day. "Sometimes, if I'm in a good mood, I'll be helpful and let people in. Then there are times at the end of the day and I'm in a hurry where I'll squeeze up tight so nobody gets a chance."

Even those uniquely Hawai'i salutes that courteous drivers give one another — a shaka sign, wave of the hand or even a raised eyebrow — when they acknowledge a kind act on the road can be the source of traffic discussions.

"It seems like you don't see that little wave as much as you used to here," said Transportation Department spokesman Scott Ishikawa. "As the roads keep getting more congested, we're losing some of those little courtesies."

But Haraga, the DOT director, said even a tiny wave to another driver can cause problems.

"Sometimes it seems like people are more concerned about waving than worrying about people in the car ahead of them," he said. "If you're going 60 miles per hour, you want to keep both hands on the wheel."