Roadshow

New tech to help you survive the second car crash

Airbags, brakes and sensors are getting wise to the danger of the crash after the crash.

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This minivan driver just met the MIC. The initial impact on its side of the highway sets it up for the second impact, with you.

NHTSA

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.

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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.   

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 drift
Your 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.

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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.

Volvo

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 on
    Resist 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.