Blind Spot Warning with Hedging (BSW-H) is a connected vehicle safety technology developed at the SMARTER Center that alerts passenger vehicle drivers when they enter the blind spots of a large truck. Existing blind spot warning systems alert only the truck operator. BSW-H warns both drivers to maximize safety response.
A Gap in Current Safety Technology
Crashes involving large trucks are a growing risk on American roadways. Large truck crashes caused 5,472 fatalities in 2023, a 40 percent increase over ten years, and 70 percent of those killed were occupants of vehicles other than the truck. Moreover, passenger vehicles account for more than 90 percent of lane change crashes with trucks. Conventional blind spot warning technology places the entire burden of avoidance on the truck driver, leaving the surrounding drivers who face the greater consequences without any alert at all.
Trucks possess unique blind spot risk, especially for small personal vehicles.
BSW-H supports visual and audio alerts.
Building In Redundancy
The term “hedging” comes from risk management: rather than relying on a single response pathway, the system introduces multiple pathways to reduce risk. Operating in a connected vehicle environment, BSW-H uses cooperative perception and vehicle-to-vehicle connectivity to detect when a passenger vehicle has entered a truck’s blind spot, then issues an in-vehicle warning directly to that driver. If either driver fails to recognize the conflict, the other is still equipped to act. The system supports both a visual alert and a combined visual and audible alert.
The BSW-H System’s hedging component is distinct from traditional blind spot warning applications.
From Research to the Road
Morgan State University holds a patent on the BSW-H system. The Center is now partnering with Toxcel to move the technology toward real-world implementation and testing. The findings also give regulators and manufacturers an evidence base for incorporating multimodal warnings into future vehicle safety requirements and for standardizing how truck blind spot zones are defined across systems.
Validated in the Simulator
Researchers evaluated BSW-H in the Center’s Safety and Behavioral Analysis Lab using a six-mile virtual model of the I-95 and I-695 corridor near Baltimore. Forty-three licensed drivers each drove three scenarios: no warning, a visual-only warning, and a combined visual and audible warning. The study produced several significant findings”
- Combined visual and audible warnings significantly reduced the time drivers spent in truck blind spots compared to no warning at all
- Drivers significantly adjusted their speed in response to both warning types
- 86 percent of participants reported that the system contributed to safer driving behavior
- 90.7 percent rated their experience with the system as excellent or good
