A one-year field study conducted by the National Highway Traffic Safety Administration's (NHTSA) has found that collision avoidance systems (CAS) can reduce if not eliminate crashes, with a majority of fleet managers participating in the study calling for this technology to become standard equipment in the industry.
NHTSA’s research – entitled Field Study of Heavy-Vehicle Crash Avoidance Systems: Final Report – sampled 6,000 CAS activations from over 3 million miles and 110,000 hours of “naturalistic driving data” in order to evaluate the reliability of those system activations – including all automatic emergency braking (AEB) and all impact alert (IA) events, according to the agency.
The result? None of those activations were associated with collisions; especially rear-end collisions due to emergency braking by the tractor-trailer.
A total of 169 drivers operating 150 Class 8 tractor-trailers from seven trucking companies across the U.S. participated in NHTSA’s one-year field operational test, driving trucks equipped with either the Meritor WABCO OnGuard or the Bendix Wingman Advanced systems.
Matthew Stevenson, president and general manager for Meritor WABCO stressed in a statement that both of those CAS systems represented “2013 vintage” technology, meaning many improvements to CAS technology were not incorporated in this research.
"While fleets report up to an 87% reduction in rear-end crashes and about 89% reduction in rear-end crash costs with the previous OnGuard system, our newer OnGuard Active will be a further improvement,” he said. “We'll take lessons learned from this study to strive for the prevention of 100% of rear-end collisions moving forward."
Some of the results from NHTSA’s study include:
- CAS activations prior to safety-critical events (SCEs) were most likely to occur in medium traffic density conditions, while lane departure warnings (LDWs) were most likely to occur in low-traffic density conditions.
- CAS activations generated prior to an SCE were most likely a result of “lead vehicle” (LV) actions, such as braking, turning, switching lanes, or merging. This finding is corroborated by 2007 research that found 78% of light-vehicle and heavy-vehicle conflicts are instigated by light vehicles around the heavy vehicle.
- In contrast, advisory forward CAS activations were most likely to be a result of “subject vehicle” (SV) actions – meaning the tractor-trailer participating in the study – such as passing, changing lanes, or following too closely.
- NHTSA said the study results suggest that the highest priority activations tend to go off in the most urgent situations, which may help the driver respond appropriately. Lower priority activations tend to be advisory, and may be useful for drivers in adjusting their general behavior, rather than in reacting to specific situations.
- Overall, CAS technologies show potential for significant safety benefits for commercial vehicle drivers. However, refinements to the technology could be implemented to address potential issues with false activations. Testing procedures for curved roads and overhead objects could help reduce false activations and improve the reliability of individual components of the this technology.