Drunken driving is more of a concern to American drivers than people who use marijuana or prescription drugs before driving, according to research by the AAA Foundation for Traffic Safety.

The findings are part of the organization's annual Traffic Safety Culture Index, which polls drivers ages 16 and older on their driving behaviors and attitudes. The survey's full results will be released later this month, but the conclusions on alcohol and drug use were released separately.

AAA says the survey results indicated an awareness of drugged driving issues, with 85 percent of respondents supporting marijuana impairment laws. The organization says drugged driving has become a greater concern in recent years, with four states and the District of Columbia legalizing recreational marijuana use. However, the study also found that respondents lacked awareness on matters such as the safety and legal ramifications of drugged driving.

"While all states prohibit driving under the influence of drugs, there's significant variation in the minimum acceptable levels of marijuana or its traces in a driver's system," said Peter Kissinger, president and CEO of the AAA Foundation for Traffic Safety. "Sixteen states forbid any presence of prohibited drugs, while five others have specific limits for marijuana. With a lack of uniformity, it's no surprise we found that more than half of American drivers were unaware of the laws that exist in their state."

ALCOHOL

The AAA Foundation for Traffic Safety found that most drivers considered driving under the influence of alcohol to be unacceptable. Ninety-two percent said they considered the behavior to pose a somewhat or very serious risk to personal safety, while 91 percent agreed that it was unacceptable for someone to drive if they think they have had too much to drink.

Seventy-five percent of respondents considered that most people in the area where they live hold a similar opinion on driving under the influence of alcohol. Forty-two percent said they think drunken driving is a more serious problem today than it was three years ago.

Respondents were also supportive of countermeasures to reduce the levels of drinking while driving. These included alcohol ignition interlock devices for drivers convicted of drunken driving, even as a first offense (80 percent); built-in alcohol ignition interlocks on all new vehicles (73 percent); and lowering the blood-alcohol level at which a driver is considered intoxicated from .08 to .05 (63 percent).

Despite these attitudes, several respondents admitted that they drove at least once in the past year when they thought their blood-alcohol level might be near or above the legal limit. Twelve percent of respondents, and one out of every five who said they drink, said they had driven with a potentially high blood-alcohol level. Thirteen percent of drivers who said they drink alcohol said they drove with a potentially high blood-alcohol level more than once in the past year.

MARIJUANA

Fewer respondents were concerned with drugged driving, though a majority still felt it was an issue. Fifty-six percent said driving after the use of illegal drugs posed a very serious threat, compared to 66 percent who considered drunken driving to be a very serious threat. Almost half of all respondents said drugged driving was a bigger issue than three years ago.

About 80 percent of respondents said they considered it unacceptable to drive one hour after using marijuana.

"Federal government research suggests that marijuana can impair driving performance for up to three hours," said Kissinger. "Decreased car handling performance, increased reaction times, and sleepiness have all been documented driver impairments that result from marijuana use."

The National Institute on Drug Abuse says studies have shown that judgment, motor coordination, and reaction time are all impaired by the use of marijuana. The organization says drivers are about twice as likely to get into an accident when driving after using marijuana and three to seven times more likely to be culpable in an accident than an unimpaired driver. The organization also warns that drivers who use both marijuana and alcohol before driving are more impaired than drivers who take either substance on its own.

In Connecticut, medical marijuana is legal but driving with any amount of marijuana in the system is considered driving under the influence. John T. Walkley, a Milford attorney, says medical marijuana users are not exempted and recommends that these residents avoid driving after using the drug.

PRESCRIPTIONS

The AAA Foundation for Traffic Safety says many prescription drugs, including over-the-counter medications, can impair driving ability in the same way as alcohol. Previous studies determined that some antidepressants were found to increase the risk of an accident by 41 percent.

The AAA Foundation for Traffic Safety has developed a free interactive tool called RoadwiseRX to better inform drivers of the effects of medications on driving ability. The tool informs drivers of the side effects and interactions of a variety of drugs.