NEW YORK (CNNMoney.com) -- One in five licensed drivers -- some 38 million Americans -- lack the knowledge necessary to pass a written driving test, and even more are distracted while driving, according to a survey released Thursday.
The annual GMAC Insurance National Drivers test polled 5,202 licensed drivers from 50 states and the District of Columbia with a 20-question test derived from state department of motor vehicles exams. A passing grade was 70% or better. The survey also asked additional questions about distracting habits such as texting while driving.
Overall scores dropped from a year ago. Licensed drivers posted an average score of 76.2% versus 76.6% in 2009.
"It's discouraging to see that overall average test scores are lower than last year," said Wade Bontrager, senior vice president of GMAC Insurance, in a prepared statement.
Nearly three out of four couldn't identify safe following distances and some 85% incorrectly responded to questions about what to do when approaching a steady yellow light. This signals that licensed drivers lack knowledge of fundamental road rules, GMAC Insurance said.
Test performance varied widely by region. Drivers in the Midwest scored 77.5% on average, the highest among all regions, and had the lowest failure rates at 11.9%. Conversely, the Northeast scored the worst with an average score of 74.9% and had the highest failure rate of 25.1%.
Drivers in Kansas topped the nation with an 82.3% average score, while New Yorkers were last on the list with a score of 70%.
Even more alarming is that Americans are increasingly multi-tasking while behind the wheel, the study found. About 25% of those surveyed admitted to driving while talking on a cell phone, eating, or adjusting their radios or iPods.
While only 5% of drivers said they texted while driving, Bontrager said that the "surprisingly low" number is still higher than it ought to be, adding that drivers may not have responded honestly to this question.
"The really sad thing is that you see [texting while driving] more and more in young drivers," said Bontrager. "They are not only the least experienced, but also need to pay the most attention to the road."
According to Bontrager, historic data supports that women tend to have fewer accidents than men, but the survey found that they were more likely to engage in distracting activities while driving than their male counterparts. And women also scored nearly four percentage points lower on the overall test than men, who averaged a score of 78.1%.
Although complete knowledge of the rules of the road won't shield drivers from all accidents, being informed helps to ensure that they are more prepared to deal with unexpected events, Bontrager said.
More money is expected to be wagered on the Mayweather vs. Pacquiao showdown than on any other fight ever. More
The U.S. economy and markets have been flat this year. More
Most victims of workplace violence are women. Immigrants and Latinos are most likely to suffer fatal accidents at work. More