I haven’t had much luck googling for stats on how often the lack of a hard-top roof plays a role in a serious or lethal accident. I imagine most modern convertibles have some reinforcements and safety features to mitigate rollovers a bit but what’s the real data on this?
I do not know the statistics.
I own two convertibles. My 2008 Toyota Solara has headrests in the rear seats that are designed to act as a roll bar. This is probably not as effective as a true roll bar but more effective than nothing. My 2015 Infiniti Q60S has rear roll bars that deploy in case of an accident. I imagine it works like air bags.
I owned an original Mazda Miata (MX-5). That had near nothing in the way of safety. No airbags, no ABS. Its one special claim to engineered safety was indeed that the windscreen surround was strong enough to carry the weight of the car when inverted. However a line drawn from the top of the arch to the rear of the car would intersect the driver’s head. So it wasn’t great. The car would score about 0/5 for safety nowadays. Apparently in a serious frontal collision it would simply fold in half. Modern variants have improved things enormously.
I loved that car, and drove it into the ground. I think it is still on the road, having been restored by its current owner. It is a very popular track car - they get full roll cages. But as a daily drive now. Nope.
Poking around on google, statistics vary a bit depending on whose numbers you are using. One of the interesting things is that overall accident rates seem to be lower for convertibles than hardtops. That might not be an apples to apples comparison, though. Convertibles tend to be more expensive cars, and the people that drive more expensive vehicles might be safer than those who don’t. It’s a bit of a stereotype, but there is some truth to younger kids buying cheap rice rockets where older, more conservative guys buy expensive convertibles.
This shouldn’t be much of a surprise, but you have a significantly greater chance of being ejected from a convertible, especially in a rollover accident, and if ejected, you have a significantly greater chance of fatality.
Convertibles do have reinforcements, partly for safety and partly to prevent body twist while driving since they don’t have the mechanical reinforcement of a hard roof structure to prevent twisting. That reinforcement in the body of a convertible is better for collisions, but a hardtop is obviously better for a rollover.
I’m going to assume that any convertible is more dangerous than the hard top equivalent.
If you do some research even a modern Jeep Wrangler seeems to be more dangerous than most other vehicles.
The Wrangler has numerous issues that decrease its safety ratings, especially the short wheelbase and high center of gravity. Those are great for off roading but increase rollover danger dramatically.
I thought IIHS had deaths per X passenger miles by model but I’m having trouble finding the data.
Although as ECG mentioned, this doesn’t account for different driver behavior.
Depends exactly by what you mean by “… doesn’t account for different driver behavior.”
IIHS data totally does account for driver behavior in the sense that actual stats from actual vehicle miles driven and actual vehicle accidents occurring is actually reporting the safety of the combined convertible car + convertible driver system.
It would take a separate subsequent calculation of dubious reliability to try to tease apart the effect of the car and the driver then apply an adjustment to be able to say “If, counterfactually, convertibles were driven by average drivers, then we’d see that convertibles would have 5% or 3% or whatever amount more / fewer accidents.”
It’s an interesting question whether convertible drivers are safer or less safe than average. Many convertibles are sporty models also available in hardtop. Sporty models that are driven harder regardless of their top style.
I wonder about “passenger miles” being the relevant measure. And how they decide how many passengers are in the average car on the average trip. Certainly a fully loaded 2-seater will have double the per-passenger mile crash results of a full-loaded four seater even if the both crash once every 300,000 vehicle miles.
I suspect convertibles are somewhat biased towards 2-seaters over 4-seaters. Yes, there are plenty of 4-seater convertibles too. But there are no 6-10 passenger convertibles, though there are lots of such vans, SUVs, family wagons, etc. All of which would still drive the stats toward fewer passengers per vehicle mile in convertibles than in hardtops.
I’m also going to suggest that convertibles are massively overrepresented in CA & FL vs. the rest of the US. Neither of those states are noted for their sane, careful drivers.
Here in SoFL, there’s a reason our local interstate is called “95”. That’s the speed of traffic.
Well, now, that’s science right there.
Haha that’s fair, I guess aside from structural integrity with a convertible there is a greater chance of ejection or say you flipped over an object or part of a guardrail or something entering the cabin of the car. I also wonder how well hard top convertibles fair against non convertibles.
I think to factually answer this question you would need a special-purpose study that collected data about collisions involving convertibles to comparable collisions involving non-convertibles. Then you also have to figure out what to do with cars like mine, which is a retractable-hardtop convertible. I don’t know if it is structurally equivalent to a hardtop when the top is up.
If you look at general statistics you might be able to get accident, injury, death rates and passenger miles. But your question is, “In a given type of accident, how does the safety of convertibles compare to hardtops?” You have to look at data for the damage and injury in that type of accident–not how often that accident occurs per passenger mile. You have to control for all other variables besides the type of car, and I don’t know if commonly available data allows you do this. That is, the way your question is worded, you don’t care if convertibles are involved in twice as many accidents, you just care about results when an accident happens.
Well, you’re using “account for” to mean the opposite of what ecg meant. You’re using it to mean that any effect from driver behavior is not controlled for in the statistics, because you think what’s relevant is the combined effect of driver behavior and car. Ecg thinks driver behavior could be a confounding factor that should be controlled for in the statistics to isolate the effect of the car alone.
Presumably the objective here is for a given driver to assess the safety of different car choices.
If (as ecg surmises) older wealthier drivers tend to buy convertibles, and older wealthier drivers tend to be more careful whatever car they are driving, then I think controlling for (eliminating) that confounding aspect of driver behavior in the statistics is correct. However, if buying a convertible tends to modify the behavior of a driver, then that behavioral effect is relevant.
Yeah. What I really meant was that “account for” as ecg used it was ambiguous and I wasn’t sure which way he meant or whether he’d even noticed the ambiguity.
You’ve done a better job than I did of outlining the issue. And much more succinctly!
Further …
If the OP was asking not from curiosity but from a desire to decide whether to buy one for himself, he’d also need to apply an adjustment for his personal circumstances. But there’s still the prereq that he’d need to know whether the reported stats were for “typical drivers” or “typical convertible drivers” to know which population to adjust himself from.