Image: Toyota
In-vehicle driver safety assistance systems are now so normalized that even the simplest vehicles are equipped with some sort of functionality, from lane departure warning to lane departure warning. But you might not want to trust some of these features into your life anytime soon, as they don’t always work as intended or as well as you think they do. Apply automatic emergency braking, as consumer reports and AAA crash tests show that most of these systems don’t work very well in a crash when you’re driving at high speeds.
While the electronics required for automatic emergency braking are complicated, how it works is fairly simple. Using sensors, vehicles equipped with AEB can usually detect an obstacle at a safe enough distance, allowing time to either avoid the obstacle or come to a complete stop. But consumer reports found that most systems don’t work when the vehicle is going over 40 mph. Worse, “none are designed to prevent ‘T-Bone’ crashes at intersections or left turns in the path of oncoming traffic.”
AAA went further and tested four popular (and unknown) models. All came with automatic braking. Using foam dummy dolls, AAA set up various crash scenarios. Their results were surprising. From consumer reports:
• At 50 km/h, the tested AEB systems prevented rear-end collisions with the dummy vehicle in 17 of 20 test drives. In the 30 mph test runs that resulted in a collision, AEB reduced impact speed by an average of 86 percent.
• At 40 mph, AEB prevented rear-end collisions in just 6 out of 20 test runs, reducing impact speed by an average of 62 percent.
• In a 50 km/h perpendicular collision at an intersection, also known as a T-bone crash, AEB did not prevent or mitigate the impact of accidents.
• AEB also did not prevent or mitigate the effects of left-turn collisions in front of an oncoming vehicle.
So if it doesn’t seem to be working as intended, what’s the point? Jennifer Stockburger, director of Consumer Reports’ vehicle testing center, emphasized that automatic braking is still beneficial because it can slow the vehicle and reduce the impact of the accident, resulting in fewer serious injuries.
But if you’re a smart driver, you shouldn’t need professional testing to tell you the obvious: don’t rely on your vehicle’s technology to save your life. While the technology we have now is impressive and advanced, none of it can explain the human factor that just pays attention while driving.