Ohioans scored an average of 78.6 percent on the 20-question test.
Ohio and Michigan drivers receive a C+ average when it comes to understanding the rules of the road, according to a study released Thursday by GMAC Insurance.
The company's seventh annual National Drivers Test shows that Ohioans scored an average of 78.6 percent on a 20-question test based on state drivers license exams. Michigan drivers were slightly behind, with an average score of 78.3 percent. The state's ranked 18th and 20th on the test, respectively.
This year's score was an improvement for Ohio, which had an average score of 77.5 percent and took 27th place in 2010. However, Michigan fell from 15th place and an average of 79 percent last year.
Take the test at nationaldriverstest.com/quiz.
GMAC polled 5,130 licensed drivers ages 16 to 65 from 50 states and the District of Columbia. Nationally, the average score was 77.9 percent, and GMAC said nearly 1 out of 5 drivers would be declared "unfit for the road" based on their test scores.
Kansas received the highest average score in the nation, 82.9 percent, the District of Columbia received the worst score, 71.8 percent.
"All Americans need a refresher course when it comes to rules of the road and it begins with education," GMAC spokesman Scott Eckman said in a statement.
The multiple-choice test included such questions as when to use turn signals, the meanings of flashing traffic lights, and proper protocol for dealing with pedestrians, school buses, and emergency vehicles.
GMAC said 85 percent of test-takers did not know what to do when approaching a steady yellow traffic light.
Liz McGarity, an office manager at Master and Sylvania Driving School in Toledo, wondered if older test takers may have missed more questions because traffic laws change over time and they haven't studied the laws as recently as teen drivers.
"I think people who have been driving a long time don't really see some of the stuff that's around them," said Ms. McGarity, who has taught classes for the school.
GMAC says drivers ages 60 to 65 had the highest average test score at 80.3 percent, and adults ages 25 to 34 were "significantly" more likely to fail the test than any other age group.