A recent Toyota study revealed an advanced driver assistance system (ADAS) developed to address intersection crashes was able to prevent or mitigate 93% of crashes in simulation, surpassing even scenarios where human drivers intervened.
Conducted by Toyota’s Collaborative Safety Research Center (CSRC) in partnership with Virginia Tech, the Intersection Crashes and Evasive Actions project focused on modeling driver behavior to inform updates to Toyota’s suite of safety technologies, including Toyota Safety Sense (TSS).
“We have the detailed scenarios, we know where the cars are coming from, we know what other objects are around… the output is automatically generated and aggregated,” said Zhaonan Sun, principal scientist with CSRC. “All these results feed into the machine learning algorithm, which is then added to the crash avoidance driver behavior model.”
Using data from 43,000 real-world crash and traversal scenarios -- including from the Strategic Highway Research Program (SHRP-2) and Virginia Tech’s VT-CAST datasets -- Toyota developed multiple driver behavior models for use in the Intersection-ADAS system, or I-ADAS.
Three high-risk intersection scenarios were evaluated: Straight Crossing Path (SCP), Left Turn Across Path Opposite Direction (LTAP/OD), and Left Turn Across Path Lateral Direction (LTAP/LD). These types of crashes represent the second-highest number of fatal crashes in the U.S.
When I-ADAS was tested without driver intervention, it activated in 93% of cases, avoiding 48% of crashes entirely and mitigating another 45%. By comparison, with a driver braking or steering, only 82% of crashes were avoided.
The finding that human intervention didn’t improve outcomes as much as anticipated surprised researchers.
“It turns out that when people are alert and they are paying attention, they can help avoid more crashes,” said Rini Sherony, who retired as a senior principal engineer at CSRC. “So, when drivers do take action and then you supplement with the automatic emergency braking, we get significantly more crash avoidance than with just the crash avoidance system. That was a very, very interesting finding.”
Sherony, who led the I-ADAS project during her final years at Toyota, said the experience was a culmination of her lifelong work in vehicle safety. “I feel like I devoted my life to improving car safety,” she said. “So, I’m retiring, but I feel like I’m kind of leaving my legacy behind in all these cars.”
Toyota emphasized that its research process involves rigorous engineering -- not guesswork.
“We don’t develop the systems out of the sky,” Sun said. “We work incredibly hard and follow a very, very detailed engineering process to be able to come up with some of the system designs.”
The findings from this project are expected to play a key role in the next generation of Toyota Safety Sense, enhancing the systems’ ability to replicate and react to real-world driving behavior.
