Craig Staniland, underwriting director of swiftcover.com, said: "Many people still take liberties while driving, and the fact that most don't know this affects their insurance is a major concern.
"We would encourage all drivers to check their policy before purchasing their car insurance so there are no hidden surprises."
The survey found that four out of five drivers admitted to speeding, a fifth had driven through a red light and two thirds had used a mobile without a hands-free kit.
Meanwhile, drivers who continually hog the middle lane on the motorway have caused more than half of those polled to undertake the car in front, while one in three admitted to tailgating a slower car in front.
Despite the relatively high levels of traffic violations, 84% of the survey participants had a clean driving licence, with only 3% ever having received a driving ban.
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