Do we really need all that safety stuff?
 

Altough it seems negligible, seatbelts and airbags do add some weight and, considering airbags and pre-tensioning seatbelts, some complexity that seems a little too much for me. I wouldn't mind if I could have lap-belts in a new car for a lower cost instead of 3-point belts, and considering that American school buses don't have seatbelts but are still deemed the safest terrestrial vehicles in the world would we really need airbags and seatbelts?

How many people do you know that got killed or hurt in traffic accidents?
How much better would they have fared if their cars were up to spec in safety, or how much worse if not?

I made the tally and I cherish those safety features, I don't mind spending a few drops of fuel extra to carry them around.

I was a passenger on a city bus that rammed a car at about 10 km/h.
Many people in the bus fell. Some got hurt.

If I drove a school bus, I wouldn't wear a seatbelt either. I drive vehicles that are less than the average weight in America, so I wear a belt.

I wonder how much weight all the airbags and related systems add? I have front, knee, and side airbags in the Prius and TSX.

That said, I also ride a motorcycle, which means I am comfortable with the danger of having no restraint system, let alone car frame.

People in the U.S. tend to be very paranoid about safety. When I asked about buying a reconstructed titled car on the Prius forum, most people thought I was crazy to even consider it. In their mind, the car could explode at any moment. Some will buy a large SUV for safety reasons, yet statistics show that we will most likely die of heart disease. If people were truly concerned with safety, they would eat less and exercise more.

;)

I'm an Anti-Braker

Weight will also increase your stopping distance... If you added up all the weight of all the safety components (including safety cells, deformable structures etc - keep in mind a heavier car then needs a heavier engine, gearbox, brakes and so on), there's probably as much as 50% of a cars mass. More mass= more accidents (partly why SUVs are crashed so often).

Example, a Metro weighed in at ~700kg, while current cars of that size are often weigh over 1000. That's before we account for the way modern vehicles are built, where weight is carefully kept to a minimum.

If you built a Metro with modern techniques (to the same crash standards), it could weigh as little as 500kg, and even less if you went with some of the more exotic materials that are now creeping in.

A 500kg car would stop in far less distance than a 1000kg one, and if you consider that 5 metres of stopping distance is the difference between stopping safely and having a severe accident, it's hard to say that safety technology does anything more than make you feel safe (which probably makes you less safe).

Breathing causes Cancer.

If you don't think that is true then just quit breathing. I guarantee you will NOT die of cancer.

Point is you can argue any point well enough to give it some validity.

The wife thought I was crazy to buy the Sentra. "It doesn't have airbags!"

But dear it has automatic shoulder harnesses so I will never get a ticket, even if I forget to wear the separate lap belt.

Going back to the era of the 50s and early 60s, I can only wonder how high the road fatalities and permanent injuries would be without.

windshields that don't decapitate people
Side guard beams that prevent terrible injuries in minor collisions
collapsible steering columns instead of spears
decent brakes versus, oh my god the pedal just went to the floor!
recycling crankcase blowby instead of a cloud of smoke identifying traffic jams
tires that last more than 6k miles

regards
mech

Sorry, but this is a misconception.
If a car is twice as heavy it will press twice as hard against the road; the tires can generate twice as much friction before they begin to give way.
A car that is twice as heavy should, all other things being equal, be able to stop in the same distance as a lighter car.

Of course the brakes need to be able to handle twice the braking force too.

If you fail to brake in time then the damage inflicted will be higher, that's true.
On the other hand, if you get hit you'd better be in a heavier vehicle as the higher mass of your own vehicle makes the resulting speed change after impact lower.

But stopping distance and vehicle mass are totally unrelated to each other.

Weight also reduces maneuverability. My piggish leaf really plows into the corners, where the prius seems almost agile (though the lighter econoboxes feel much more agile than the prius).

The same goes for that, a heavier car can also provide more sidewards friction so it should - in theory - corner just as fast as a lighter car.

A smaller car would feel more nimble, as it has a smaller footprint so it reacts (rolls) more to changes in direction or speed than a big car would. But that's relative to its size, not absolute.

There are big differences in suspension setup between cars. That alone may cause your Leaf to feel heavy compared to the Prius.
Most high performance sports cars are heavier than either, but nobody would say they are less agile.

That's fine in theory, in the real world you could use softer tyre compounds with more grip and similar wear characteristics.