I would have thought your harness will provide greater safety in most situations such as side on collisions holding your body inplace better perhaps reducing the chances of hitting your head on the door. I guess it would also reduce some of the damage caused to the chest by spreading the force to the chest over more than one strap, then again that is a fairly marginal injury in comparison.
The HANS device is without doubt one of the more important safety devices when combined with a good harness as the HANS device is held in place by the harness. This would be a much better way of preventing neck injuries rather than an airbag (and without the broken nose
).
Of course then you have you safety helmet which prevents objects to the face qutie nicely, not much to discuss other than that.
Roll cages of course provide great rigidity to the car in general, this is very important in crashes, particularly in the event of a roll over. As has been mentioned already, they don't do the cranium any favours when in a high velocity impact. This of course means while greatly helping you from getting crumpled along with your car in a crash may just kill you with head injuries if no helmet is worn.
So really what I am saying is that if you're going to put in a roll cage you are going to need space for it (not a problem for a stripped out race car). If you are going to have a roll cage then you are going to want a helmet to prevent it from killing you. Ok but if you are going to wear a helmet then you might aswell chuck in the HANS device for good measures, but for your HANS device to work then you need to be tightly secured. So you might want to go for your 5 or 6 point racing harness. If you want your Racing harness to work correctly you need to fasten them to the cars frame rather than the seat which means your rear seats have to go (again not a problem for a racing car). Then to finish the job you might aswell throw in a handy fire extinguisher. For the really scared people you could always construct an nice carbon fibre monocoque to help prevent that cockpit intrution.
Misfortune has it that these (exceptionally good) safety measures just aren't practical enough for your daily commute, most people wouldn't give up their rear seats for the 5 point harness, as Clarkson pointed out people generally don't want 'scafold' in their car. To top that people wearing a helmet and HANS device would look a complete plebb driving down the road unless they where in a racing car (in which case you would probably wonder why they are driving a race car on the road), which again doesn't appeal to most people, if I am honest it doesn't really appeal to me that much, unless I wanted a track car of course.
To sum it up, when
combined these safety measures can really improve your safety quite dramatically. But the measures required to combine these safety devices make them completely impractical use for general road use.
Race cars have no such problem because;
A) Race cars aren't required to be practical
B) You don't look a tool when using the correct saftey equipment on a race track, conversely people who don't use the correct safety equipment on a race track look a tool.
C) Race cars are more likely to crash than normal road users so it makes sense to have safe cars despite the cost.
D) Impacts on a track that normal safety equipment to protect you from particularly well, tend to require more versatile safety equipment. E.g rolls aren't as frequent in normal driving compared to your average shunt. In things like rallying rolls are common and are therefore pose a more prominent danger when not properly protected.
Hope that helps answer your question. 👍
