Openly criticizing a spouse's driving is a good way to spark a nasty argument or find yourself spending the night on the couch. Behind the anonymity of a survey, however, people were more likely to criticize a loved one's skills behind the wheel while still considering themselves to be good drivers.

In a survey commissioned by the driver training site eDriving, 85 percent of respondents said they were a very good or fairly good driver. Men were slightly more likely to hold this opinion, with 88 percent saying they were fairly or very good drivers compared to 82 percent of women. Older drivers were also more likely to think highly of their own driving skills, with 89 percent of those ages 55 and older holding this opinion.

When asked to rate their spouse's driving skills, only 55 percent considered them to be a very good or fairly good driver. Women were slightly more charitable, with 58 percent considering their spouse to be a good driver. Fifty-one percent of men held the same opinion.

Four percent of men described their spouse or significant other as a bad or not very good driver, compared to 1 percent of women who held the same view. Only 2 percent of respondents described themselves as a bad or not very good driver.

Young drivers were most likely to have a critical opinion of their spouse's driving ability, with only 40 percent of those between the ages of 18 and 34 saying they were a very good or fairly good driver. However, the next oldest age group—those between the ages of 35 and 44—had the most positive opinion of their spouse's driving among all ages groups, with 64 percent saying their spouse was a good driver.

"The discrepancies here point out an interesting and important truth: most drivers are overconfident, and the people who drive with them the most are probably very aware of their bad habits behind the wheel," said Celia Stokes, CEO of eDriving.

Respondents also held unfavorable views of how well their parents drive. Forty-four percent considered their father to be a good driver, and 40 percent thought their mother was a good driver. Eight percent said their mother was a bad or not very good driver, while 4 percent had this opinion of their father.

People were less likely to approve of a parent's driving ability as they got older. While 69 percent of the 18-34 age group considered their father a good driver and 63 percent approved of their mother's driving ability, these shares shrank to 19 percent and 14 percent, respectively, in the 65 and older age group.

Only one-third of respondents considered their children to be very good or fairly good drivers. Men were more critical, with 28 percent holding this opinion versus 38 percent of female respondents.

In a reversal of the earlier trend, respondents were more likely to approve of their children's driving ability as they got older. Just 15 percent of the 35-44 age group considered their children to be good drivers, but this share increased to 73 percent in the 65 and older age group.

Hale Gammill, an eDriving instructor, says people should keep in mind that children learn their first driving skills by observing their parents. Young drivers are more likely to tailgate, speed, use a cell phone, or otherwise drive irresponsibly if they witness similar behavior from their parents.

"Parents must remember that they are really their children's first driving instructor," said Gammill. "If they want their children to be better drivers, they must model better behavior and raise the bar when it comes to driving skill. And that starts with knowing what they're doing wrong. Raising a good driver is not about avoidance, it's about active practice and conscious and continuous learning. Finding out what your passengers think you're doing wrong is a great first step."

Fifty-eight percent said they usually travel with a spouse or significant other on a road trip. The 35-44 age group was most likely to go on a road trip this way, with 68 percent saying they traveled with a spouse or significant other.

Nineteen percent of all respondents—and half of the 35-44 age group—typically traveled with children who were not of driving age. Sixteen percent regularly traveled with their mother or female friends, 13 percent with male friends, 12 percent with children of driving age, and 10 percent with their father. Nine percent usually took road trips alone, and 2 percent traveled with co-workers.

Thirty-six percent of respondents said they do not get into any arguments with other occupants of the vehicle during a trip. Older respondents were less likely to have disagreements on the road, with 56 percent of the 65 and older group saying no arguments typically come up during a drive.

Music was one of the most common causes for disagreements, with 29 percent saying they get into disputes over who gets to decide what tunes to play. Younger respondents were most likely to disagree on this subject, with 49 percent saying they argue over music.

Arguments over speed were also commonplace, with 29 percent of respondents saying they got into disagreements over whether the vehicle was traveling too fast or too slow. Younger drivers were again most likely to argue over this subject, with 32 percent of the 18-34 age group and 35 percent of the 35-44 age group saying the subject came up during drives.

Twenty-seven percent said they have had disagreements over the temperature inside the vehicle. Sixteen percent said they have argued about where or when to stop for a break, 12 percent about finding a parking space, and 6 percent over who gets to drive.

The online survey, conducted by Harris Poll, polled 2,012 adults between June 30 and July 2.