By Mike Davey
Toronto, Ontario -- February 1, 2016 -- It looks like collision warning systems and automatic braking are effective at reducing the number of certain types of collisions, according to a recently released report by the US-based Insurance Institute of Highway Safety (IIHS).
The study, “Effectiveness of Forward Collision Warning Systems with and without Autonomous Emergency Braking in Reducing Police-Reported Crash Rates,” was prepared by Jessica B. Cicchino and looked at vehicles equipped with forward collision warning (FCW) alone, and also at cars that had both FCW and autonomous emergency braking (AEB).
The report only included vehicles that have FCW systems as a factory option. However, it’s important to remember that some third-party companies also manufacture similar systems for aftermarket installation. These systems, such as that manufactured by Mobileye, can be added to any vehicle and would likely have a similar impact in preventing or mitigating collisions.
The report compares rates of crashes reported to the police in 27 US states between 2010 and 2014. The data used included both equipped vehicles as outlined above and the same models that did not have those optional systems. This controls for other collision avoidance systems and other factors affecting crash risk.
The results are striking. FCW alone and FCW with AEB reduced rear-end collisions by 23 and 39 percent, respectively. Looking outside rear-end collisions, FCW alone reduced involvement in all collisions by 12 percent and in multi-vehicle crashes by 11 percent. The vehicles with AEB were found, across the board, to be involved in fewer collisions resulting in injury.
According to a statement from the IIHS, if all vehicles had been equipped with automatic braking that worked as well as the systems studied, there would have been at least 700,000 fewer police-reported rear-end crashes in 2013. That number represents 13 percent of police-reported crashes overall.
"The success of front crash prevention represents a big step toward safer roads," says David Zuby, IIHS Chief Research Officer. "As this technology becomes more widespread, we can expect to see noticeably fewer rear-end crashes. The same goes for the whiplash injuries that often result from these crashes and can cause a lot of pain and lost productivity."
Collisions in which equipped vehicles were struck from behind but did not then strike another vehicle were left out of the data, as FCW could not be expected to prevent these types of collisions.
There are challenges to studying the effectiveness of FCW technology. For one thing, many of the vehicles in the study also have adaptive cruise control, which means the vehicle will automatically maintain a “safe” distance from the vehicle in front when the system is active. It’s possible that some of the collision prevention seemingly obtained from crash warning is actually a result of adaptive cruise control. A number of the vehicles were also equipped with lane departure warning, but it’s believed to be unlikely that this would affect rear-end collision rates.
The entire report is available for download at “Effectiveness of Forward Collision Warning Systems with and without Autonomous Emergency Braking in Reducing Police-Reported Crash Rates.”