The lack of a roof does not mean a lack of safety when it comes to cars, according to an IIHS study released on Tuesday.
Even with cloth tops, modern convertibles don't pose a greater crash and fatality risk than sedans or coupes. In fact, there were fewer crashes and fatalities in convertibles. An analysis of crash fatality data of convertibles that were up to five years old during 2014-2018 showed that convertibles were involved in 6% fewer crashes per miles traveled and death rates were 11% lower than in conventional cars.
"There's no statistical basis for concerns that the lack of a permanent roof makes them more dangerous," said Eric Teoh, IIHS director of statistical services and author of the study.
Other studies echoed this point. Convertibles had fewer insurance claims and lower injury rates when compared to nonconvertible versions, according to a study released this year by the Highway Loss Data Institute.
In recent years, automakers have voluntarily enhanced safety systems in convertibles by strengthening the A-pillars on either side of the windshield or installing roll bars, according to the IIHS. Convertibles generally aren't crash tested by the IIHS and don't qualify for Top Safety Pick awards because they can't be tested for roof strength, which is one of six key tests performed by the IIHS. The 2020 Ford Mustang convertible is the only convertible tested recently, according to IIHS spokesman Joe Young, and it earned top "Good" ratings in side, front overlap, and head restraint tests.
Those enhanced safety systems haven't prevented occupants from getting ejected from the convertible at a higher rate than drivers killed in nonconvertibles, however. The IIHS found that 21% of convertible drivers killed in crashes were ejected from the vehicle, compared to 17% for regular cars.
Other factors to consider that would be hard to quantify are the likelihood that convertible drivers may be more likely to drive when the weather is nice or in the daytime. Nighttime crashes make up about half of all traffic fatalities, and that's typically when there are fewer cars on the road. The crash data, pulled from the NHTSA's Fatality Analysis Reporting System and its successor, found that convertible drivers were slightly more likely to be wearing seat belts and less likely to be speeding, but they were slightly more likely to be impaired while driving.
“Based on this study, convertibles don’t appear to pose a particular safety risk,” Teoh said.