Built-in car safety has made huge advances

Crash test

The causes of serious injury in car accidents has been very thoroughly researched by manufacturers and independent safety organisations.

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Are “NCAP” safety ratings mostly just theory and hard-sell, or do they make a significant difference in the event of a severe accident?


Short answer: There are no designs or tests that cover every possible crash situation, but NCAP (New Car Assessment Programme) physically assesses the most crucial safety features – not just whether they are part of the design, but how well they actually work in a severe crash. The test drives cars at speed into deformable concrete, from different angles, watches the process with specialised slo-mo cameras, and looks at the result with an expert eye, precise measurements, and reams of computerised data on angles and forces. It also rolls cars upside-down. Their results are definitely meaningful in practice. NCAP issues grades from 1 to 5. The higher the number the better. Because there is not a 6, some of the cars that score 5 have merely (and perhaps only just) achieved the top benchmark, others might have far exceeded it.

US NCAP started in 1979 and is compulsory. Euro NCAP started in 1996 and it is voluntary. Others followed, e.g. ASEAN NCAP in 2011.

Longer answer: The evolution of safety features has been continuous. At the very beginning of motoring, it started with things like electric lights (not gas tablets that went out when a car hit a bump) and rear-view mirrors (which were initially a “portable extra” that was often kept in the glovebox), windscreen wipers (that had to be twisted by hand), brakes that did more than generate smoke and rude smells…and sometimes fires under the wooden floorboards), and tyres with air in them (the first inner-tubes were inflatable rubber skins in the shape of a sausage wrapped round the wheel rim and protected with a hard rubber casing; only later did manufacturers discover how to mass-produce tubes in a continuous 360 degree circle.)

Competitive motoring (racing and rallying) drove advances in things like steering geometry, suspensions, better tyres, servo-assisted and then and disc brakes. The quest for all aspects of “performance” (and a better chance of staying alive while using it) was the mother of invention and motivator of safety aids.

Once very much better control of the car was achieved (making accidents less likely though not much less lethal) the safety of a car in an accident was generally presumed to rely on its structural strength, and, especially in collision with another vehicle, its weight. Weight was less significant in collisions with immovable objects such as stout trees or concrete pylons.

From the 1960s, when high speed traffic became dominant and markets demanded very much lighter vehicles in the quest for lower construction costs and prices, higher speeds and better running economy, the weight and strength principle had to be reviewed. And research showed it was by no means the best way to keep drivers and passengers safer. On the contrary.

Bend the car, not the passengers

If car body did not bend, the full force of an impact (going from 80kph to 0kph in the space of a couple of metres) was transmitted to the unrestrained people inside it (who thus went from 0kph to 80kph into the dashboard and windscreen). If, instead, a car crumpled, some of that force was absorbed. Then again, if the car crumpled too easily, the people inside would simply be squashed. The recipe that emerged was a front end that progressively absorbed shock…but only up to the passenger compartment, which was made very much stiffer as a “safety cell”.

At the same time, the remaining shock force was moderated by safety belts, and then head restraints to counteract whiplash. These developments were a quantum-leap advance in safety standards.

From reducing accidents to reducing injuries

As the world’s vehicle population surged towards a billion (we are now well past that milestone), the causes of serious injury in car accidents has been very thoroughly researched by manufacturers and independent safety organisations. Well-known successors to the safety belt, crumple zones, the safety cell, burst-proof doors, and child safety locks include a rounding and softening of all the fittings on and around the dashboard and door panels and, more recently, airbags. All, once established, have become progressively refined.

And that is not all. With cumulative road death tolls still exceeding anything achieved in outright warfare, focus has been on further reducing remaining “causes of injury” in collisions severe enough to push the engine into the passenger compartment, spear the steering column into the driver’s chest, snap ribs against a seatbelt, mangle ankles as the pedals are pushed into the footwell, and crack vertebrae and pelvis bones if the seat slides or folds forward or snaps on rebound.

How well do safety aids work?

NCAP examines whether (and in what way and to what extent) the airbags effectively deploy, how well the progressive crumple zones of the front absorb impact energy, whether steering columns fold inside the bonnet so the steering wheel itself does not move, that the engine mountings break in deliberate sequence to send the engine downwards to the ground and under the floor, and that nothing from the engine compartment enters the passenger safety cell; that the safety cell itself remains in almost perfect shape – so perfect that the doors (which should stay shut on impact) can still be opened normally. In the best designs, and illustrating how effectively crumple zones absorb shock energy, even in collisions severe enough to ram the front bumper right up to the dashboard bulkhead, the windscreen sometimes doesn’t even crack, and driver and passengers - who, not many years ago, would almost certainly have suffered life-threatening or life-ending injury - have a good chance of getting out and walking away (albeit dazed and perhaps badly bruised).

Those sort of things, and the integrity of the safety cell in a roll-over, are what NCAP physically tests and measures. Cars that tick every box get a 5. For scores of 4 and below, one or more of those protections is either missing or does not work as well as it needs to. The latest research is now focusing on car designs to reduce injury to pedestrians if they are hit by a car.


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