Would the inclusion of heavy-looking internal rollcages and 5 point seatbelts as seen in WRC race cars make common roadgoing cars significantly safer in collisions? Rollovers?
It would only make cars safer if you could actually get people to wear them. If we can’t get them to reliably weat lap belts I’m not sure how you’re going to get them to wear a full harness outfit.
Just answer the question please, Ma’am. What happens to stupid, non-seatbelt-wearing people is of no concern to me, it’s just natural selection at work. 
It occured to me that many people buy SUVs because of their perceived safety in accidents. We already know that SUVs are less safe for everyday driving due to the higher risk of rollover, I am wondering what the ultimate “safe” vehicle for transporting families should be. It seems obvious to me that a big step up would be five or six point harnesses for all occupants and supportive racing seats/headreasts. AWD and traction control would be a given, but I am not sure about the rollcage. I’ve seen many sports cars that have them installed aftermarket, and I imagine they are fairly effective for roll-overs, but what about collisions?
It would seem to me that a light, nimble AWD car like the Subaru WRX STi with racing belts and a heavily reinforced(with said rollcage) body would be quite safe even in a collision with a larger vehicle, abeit somewhat less comfortable. Thoughts?
If you could walk into a dealership and buy cars w/ 5 pts. and roll cages you’d have even more idiots playing Talladega on the freeway. :rolleyes:
People simply won’t go through the hassle of putting on a 5-point belt. It makes it impossible to do many of the tasks we normal people expect to be able to in cars.
Roll cages would certainly make cars safer, but at the cost of weight (gas mileage) and reduced usable space inside the car.
You could also add that we’d be safer if we all wore helmets, but that’s not going to happen either.
Well, since I don’t do anything else when I’m driving, and I don’t really give a shit about gas mileage, it sounds like a pretty good deal to me. 
Let me just say again, I’m thinking of what an idea car would be for ME, and my primary concern is safety. If “normal” people cannot drive without a DVD entertainment system and a coffee in one hand, it’s of no concern to me or my question.
Helmets might be a little too much though, I think they impede visibility, hearing and may not be usable on smaller cars without headroom, especially with the rollcage.
Problems: AFAIK racing seatbelts tie you in so securely that you would not be able to turn around to see when backing up and many people would not be able to reach controls farther than an arm’s length away. Try sitting in your car and reaching all of the controls without leaning forward or to the side. It’s harder than you think.
I don’t think it will be a problem to undo the seatbelt when backing up. As for the controls, well, I can live with fewer creature comforts for the sake of safety, and I’m sure one can do things about the controls.
OK, I’ll go out on a limb and say “Yes, rollcages and 5-point harnesses would make collisions and rollovers more survivable compared to cars lacking those safety measures”.
They are used in race cars for a reason - it’s not unheard of for those vehicles to get into collisions and rollovers at very high speeds and everybody involved wants the drivers to be able to walk away from accidents. And they do. Obviously the things work.
Whether people will actually USE a 5-point harness is a different question and it’s not what the OP is asking…but yeah, some people will use it, some people will reject it for whatever reason compared to their lap/shoulder belt, and some people just won’t use any safety device, ever.
And another questions is whether rollcages or improved seatbelts (or HANS, helmets and other stuff) will result in MORE accidents due to decreased visibility or mobility. Again, not what the OP is asking.
I think the answers to your questions are no, and only for convertibles.
Race cars are made to go fast. They tend to be light and built for speed rather than for durability. And they tend to be used around other cars going fast very close to them, with a greater chance of hitting something and flipping. The 5-point harnesses probably make a much bigger difference in these vehicles than they would in everyday ones, which are often designed with crash protection as one of their priorities.
Likewise, everyday vehicles with solid roofs are generally fairly resistant to being flattened in event of a rollover. Many race cars are/were convertibles, where a roll cage was the only thing keeping the driver’s head from scraping the pavement, and even the roofed ones probably aren’t as “flat-resistant” as passenger cars.
In other words, the problems encountered in racing that these devices address aren’t so much of a problem in normal driving situations, and I don’t see that there’s much to be gained by using them there.
And I was answering in the context asked, would they make everyday cars significantly safer.
Let me expand my question a little. I’m well aware that these features will make a race car more safe, but what about common roadgoing cars? I’m not an engineer, but it would not seem inplausible to me that race cars can actually be VERY usafe if not for the rollcage and what not, because in addition to being reasonably safe, it also needs to go FAST and be LIGHT. Therefore, while I can conclude that a rollcage is better than nothing, I can’t conclude that the addition of a rollcage into a modern roadgoing car, equipped with side curtain airbags and other things presumably not found on race cars, will categorically improve safety, especially in the case of collision with a larger heavier vehicle, of which on today’s roads, there are many.
Thank you Gary T. To flesh out the question a bit, if crash protection was one’s primary concern, would it be more prudent to buy a smaller, more nimble vehicle and add in a rollcage, instead of buying a large SUV? I really hope so, because I’d much rather driver the former instead of a land yatch and I’d like to think that I was better protected.
Safety is relative to the equipment in the vehicle and a driver’s ability to drive safely. While the addition of rollbars and 5-point seatbelts will change the road statistics a bit, unless all drivers learn to drive better, the death and injury rate will decrease only so much before leveling off, and possibly increasing again.
In addition your safety on the road is not merely continget upon your protection and ability to drive safely. It is also contingent upon all other vehicles on the road and those drivers as well.
If crash protection is the primary concern, I think the best choice might be a Volvo or similar car that (apparently) makes it a higher priority than average. More nimble than an SUV, safer than a small car, not really in the “land yacht” category, and forgoing the expense and inconvenience of installing and living with a rollbar. You might want to find the government crash protection ratings for different vehicles. I think they’re a reasonably reliable guide to real-world experience.
So, then, the collective wisdom of the SDMB will conclude that the improvement to crash protection provided by a roll cage and 5 point harness is not really worthwhile on a modern roadgoing vehicle?
In my mind, it still seems that a smaller family car, will come out much better fromk a collision with a larger SUV with a massive internal roll cage and racing seatbelts than without. I freely admit that I have no real basis for this impression.
Would roll cages make safer? Answer is a qualified maybe.
Why do you want a roll cage? To keep the roof from crushing in? Why not buy a car with a strong roof instead?* Want an SUV instead?**
Here is the problem with retrofitting a roll cage into a street car. In a street car things are placed with quite a bit of thought to making sure that your head or other parts of your body don’t get damaged in an accident. Knobs are moved or redesigned to prevent injury. Installing a bunch of 2-3" steel tubing fucks this up in a major league way. Ever bang your head on a roll cage? I have and it hurts. In a race the driver is wearing helmet. Helmets are not practical for on street use in car.
five point belts in a car? Not planing on having any dates are you? 
If you can get your date to fasten (Or let you fasten) the antisubmarine belt on a first date you are dating a different class of women than I did. Picture your grandmother in a dress hiked to her waist, trying to get the antisubmarine belt fastened. Pass the brain bleach please.
I have built street legal race cars with cages and 5 point belts. They are not practical. Let me repeat they are not practical.
First off it is a bitch climbing over the side impact bars. Then you have the issue of your head hitting the cage if you move in the wrong way. Next is the problem of the back seat. A roll cage turns a 4 door 5 passenger car into a coupe. The bracing makes the rear seat unusable.
Finally it takes too long for a person to adjust and fasten 5 point belts. A new driver passenger might require 5 minutes of adjusting to get the belts to fit right.
*Yes it is real. They built them that way to keep moose from taking the top of the car off, the side benefit is it is stronger than hell in a roll over
** 35 MPH roll over test. This is pic is on the first bounce after the first hit.
Well, I’ll try going for the girls that don’t particularly care about the kind of car I drive, and once I get them in the car they’re not going to get away very quickly! 
…but yeah, I get the fact that roll cages aren’t the most practical safety feature, but the thought of being crushed/pulverized by some soccer mom’s land yatch does make it seem quite appealing, and besides, I bet I’d look like a real cool cat with one too.
Well, dammit, on preview I see that Rick has beaten me to the punch on some of the points I was going to make, but here’s my take anyway.
No. In race cars roll cages only have to protect the driver, not a four- to six-passenger compartment. Protecting one person from collision requires a far less massive structure. Also, a race car with a full cage typically doesn’t have doors that open: the driver climbs in through the window. This would probably not be acceptable to your average soccer mom. In a street car, doors that open, made of steel panels, and equipped with side airbags, are more efficient–and convenient–than a cage could be.
Yes. A rollcage (or rollbar) in a street car would provide greater protection against rollovers than standard construction. (I’m going to respectfully disagree with Gary T on the level of rollover protection of most street cars.) However, this is not a high priority in the design and construction of street cars because out on the street rollovers are much rarer than collisions. They are proportionally more common on the racetrack. So in general, the level of protection street cars and race cars offer against various hazards is roughly proportional to the likelihood of their encountering those hazards.
(Coincidentally, just today I saw pictures of a 350Z–virtually identical to mine–that rolled. The A pillar collapsed and the roof flattened. The only thing that saved the instructor passenger was the fact that he was relatively short.)
Sorry. In any collision between two objects, the heavier one is going to come out better, all other things being equal. So although it is possible to create an extremely lightweight high-tech vehicle that offers great crash protection (which is effectively the definition of a race car), it will be much more expensive than a heavier vehicle with conventional construction. For instance, those WRC cars that look like ordinary sedans with some extra features cost about $250,000 each!
Nimbleness offers very little in the way of protection, and is much more dependent on driver skill than vehicle design and plain old mass.
BTW, I drive a car with a rollbar and a five-point harness. (I have a helmet, too.) What others have said about the inconvenience of the harnesses is exactly right. I only use them on the track, never on the street. It takes at least a minute to get into and adjust the harnesses, compared to about three seconds for a the standard belt. Standard three-point belts are very effective and a great compromise between convenience and safety.
Another thing that has come up w/r/t five and six point harnesses among the group of guys I see at the track is the issue of head restraints. Once you’ve got your body cinched down without the upper body motion that a three point belt allows, you greatly increase the chance of severe neck and spine injuries as your head can still move forward freely in an accident. You can end up with a basal skull fracture or similar. Most of the guys I know have added a HANS device or are at least thinking about it. Not being able to signifigantly turn your head seems like a real drawback on the street.