© CNET Volvo is one of the carmakers that has rear crash sensing tech to apply the brakes when you're about to get rear-ended, diverting some of the impact away from your car getting launched. |
By Brian Cooley, Roadshow
Somewhere between 25% and 40% of all car crashes aren't one crash,
but several. Your current car probably isn't smart enough to figure that
out, but your next one might be.
Meet the MIC
Multiple
Impact Crashes (MICs) happen when your car has one impact and then hits
another car, a stationary object or flips on its roof. The most common
is, of course, the rear-end collision that results in another one, but
the combinations are endless and impossible to anticipate in all those crash-test videos you've watched with morbid curiosity.
A 2018 study of crash data by
ProBiomechanics and Ford safety guru Henry Scott found that two-impact
crashes account for 20% of all collisions but also 30% of all severe
injury incidents. It's even more stark for three-impact crashes. They
account for just 5% of all collisions but 13% result in severe injury.
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Helpless airbags
One problem is that your
car's airbag control module (ACM) can get confused by multiple impacts
that happen literally in the blink of an eye. The ACM may fire the
airbags too early, too late or not at all. Hyundai appears to be the first carmaker
to develop an ACM that can roll with the punches, calculating force,
angles, and position of occupants in real time to fire airbags optimally
in the fray.
The deadly driftYour first impact
may be fairly benign but if it sends you drifting into the path of an
oncoming car it gets malignant, and fast. Ford and Continental have developed new post-crash braking tech
that prevents the deadly drift by detecting the immediate aftermath of a
collision and applying the brakes for a brief time. That stops your
ricochet, but doesn't render the car immovable for emergency responders.
It debuted standard on the 2019 Ford Edge.
Brace yourself
The first car I reviewed that knew how to brace itself for impact was the 2016 Volvo XC90. It gets on the brakes when it can tell you're about to get rear-ended at
a stop. That helps transfer crash energy into the car rather than your
neck while also reducing the chance and degree of a secondary impact. Mercedes Pre-Safe Plus package does something similar.
Even without the latest car, you can replicate some of these benefits for free with good driving technique:
- Wheels straight When waiting to turn left at an intersection, don't pre-cock your wheels in that direction. Keep them straight until you actually start your turn. If you do get rear-ended, you are less likely to be propelled into oncoming traffic.
- Brakes onResist the temptation to let off your brakes and shift into neutral at a long stop. Applied brakes and engaged gears create some useful opposition to the force of being hit.