Development and Implementation of a Fuzzy Logic-Based Blowover Algorithm

Wyoming experiences high winds posing a persistent threat along the Interstate 80 (I80) corridor, which reaches elevations of up to 2400m (8000 ft) above mean sea level
(MSL). High winds pose a risk to freight traffic, which constitutes half of the daily
average traffic volume on this heavily trafficked route. Truck blowovers are the
predominant type of non-collision crashes in Wyoming, resulting in losses and
necessitating road closures. In 2017 the Wyoming Department of Transportation
(WYDOT) had 700 commercial vehicle accidents and more than 1,000 hours of road
closures due to weather. In response, the Pikalert® System, developed by the NSF
National Center for Atmospheric Research (NCAR), was used in the WYDOT
Connected Vehicle Pilot (CVP) Deployment to reduce weather-related crashes along I80. Pikalert combines vehicle and weather data to generate warnings for users but
lacked an algorithm for truck blowovers. This paper takes a retrospective on the initial
development and implementation of a fuzzy logic-based blowover algorithm. Wind
parameters were refined based on findings from blowover case study analysis and
verification testing during the winter of 2017–2018. Wind gust speed and differential
were found to be the most influential parameters across all vehicle classes, as sudden
lateral forces destabilize high-profile, low-weight vehicles. This work remains actively
used in Pikalert and WYDOT operations. The broader impact and merit of this work is
to support transportation agencies for preemptive roadway closures and vehicle
restrictions during high wind conditions, thus reducing rollovers, roadway closures, and
mitigating road weather related economic losses.