Crash Simulations Paving Toyota’s Path to Safety

Before the world gets too far over its skis when it comes to installing advanced driver-assistance systems (ADAS) and automated driving technologies in vehicles, Toyota would like to know just how safe they really are.

That takes research and lots and lots of computer simulations that have the glorious resolution of a 1995-era video game.

Rini Sherony, a senior principal engineer for Toyota's Collaborative Safety Research Center in Ann Arbor, MI, spoke at the virtual CAR Management Briefing Seminars recently and showed off some of these low-resolution videos.

The important part is not how they look, but what they reveal.

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What Toyota has found, in short, is that even with 100% penetration of the kinds of active and passive safety systems we know of today (lane departure warning, emergency braking assist, etc.), the U.S. likely would only see 54% fewer fatalities and injuries in 2050, compared to the 2015 baseline numbers Toyota used and assuming the same number of vehicle miles traveled.

"Toyota's approach to safety is two-pronged," Sherony says. "First we look at everything, not only people both inside and outside the car, but the vehicle and the traffic environment. All of this together contributes to safety hazards and safety issues."

Toyota already offers active safety features through its Toyota Safety Sense and Lexus Safety System technology bundles, but the company wants to better understand the kinds of accidents that are happening on the road today as it plans to expand ADAS and automated-driving offerings in the future. 

"We do in-depth accident investigation and analysis to see what crashes are happening and how they're happening, because knowledge of that is critical to making an effective [safety] system," Sherony says.

According to NHTSA, traffic fatalities in the U.S. dropped from a recent high of about 44,000 in 2005 to 33,000 in 2010 and 2011, Sherony says.

Following the Great Recession, fatality numbers rebounded along with the economy, and they have been increasing since then to around 39,000 in 2018.

Toyota partnered with Virginia Tech to analyze official crash databases and turn the statistics into thousands of simulated crashes.

MBS Toy Sherony safety

Then, the simulated vehicles were equipped with different configurations of safety technologies, and the simulations were rerun (and rerun, and rerun) to see if there was any change to the expected number of fatalities and injuries.

This gave the company insight into which technologies would be the most effective to increase pedestrian and vehicle occupant safety.

Even when every vehicle was given every technology, Toyota calculated the aforementioned 54% drop, which suggests the "zero" accident future many in the industry – including Toyota – are aiming for remains a far-off goal.

In some simulations where a crash could not be avoided, the safety technologies did manage to avoid a fatality and resulted in minor injuries instead, so there are benefits to be had even if crashes are still around in 30 years.

Toyota also analyzed the kinds of vehicles involved in crashes as well as the types of crashes that kill people, whether it's a head-on or offset crash or rear-end and so on.

It turns out that offset crashes kill more people than head-ons, but the most dangerous type of crash is "road departure," which makes up over 35% of all fatal crashes. Toyota needs this kind of data to understand and develop countermeasures, Sherony says. 

"It is important to understand and estimate proactively before all of these [safety systems] go on the road because then we know what gaps are remaining and how we can fill in the gaps," she says. 

Using almost 2 million crashes from 2015 as the baseline, Toyota's research reveals the most effective technology to reduce crashes would be 100% implementation of rear-end automatic emergency braking (AEB) systems, which could prevent over 350,000 crashes a year in 2050.

The second-most effective technology is animal AEB (198,000), followed by Straight Crossing Path Intersection-ADAS (87,000).