LOS ANGELES (CBS) — The next time you’re driving down the street, keep an eye on that car next to you: chances are it’s being driven by someone who doesn’t know what to do at a yellow light.

A new survey released this week estimates nearly one out of every five motorists cannot pass the written test given by the Department of Motor Vehicles, with male drivers scoring significantly higher than their female counterparts.

Among the surprises: 18 percent of drivers could not pass a test comprised of 20 sample questions taken from actual DMV tests in various states, while men demonstrated a better grasp of driving rules than than women on average, with scores of 80.2 percent topping females’ 74.1 percent.

In fact, over 27 percent of female test takers failed with a score below 70, compared with 13.6 percent of men who received a failing grade.

The sample of 5,130 licensed drivers aged 16 to 65 across all 50 U.S. states showed that 85 percent of respondents did not know how to react when approaching a steady yellow light, while 75 percent were mistaken about proper safe following distances.

But despite the results, Scott Eckman of GMAC Insurance, which conducted the study, told KFWB 980’s Michael Shappee that just because some drivers may have scored higher than others doesn’t necessarily translate to superiority behind the wheel. https://losangeles.cbslocal.com/wp-content/uploads/sites/14984641/2011/05/driving-test-final.mp3

“Don’t draw the conclusion that driving behaviors and knowing the rules are correlated,” said Eckman. “There’s one thing to know the rules, another thing to obey the rules.”

“I’ve been in L.A., and I can promise you everyone is not obeying the rules,” he added.

If the results hold up nationally, the study’s findings would work out to an estimated 37 million drivers across the U.S. who would fail a driving test.

And despite L.A. arguably claiming the title of “the driving capital of the world”, those drivers in the Midwest scored highest in the nation at 77.5 percent, while the Northeast was the worst at nearly 75 percent.

The Midwest had the highest average score, with 77.5%. The Northeast was the worst, with 74.9%. Kansas had the highest state score, with an 82.9% average, while the District of Columbia was last with 71.8%.

Want to see how your driving skills stack up? Take the test for yourself at the GMAC website.