WASHINGTON — On June 11, the National Transportation Safety Board (NTSB) released its final report on the probable cause of a 2018 multivehicle crash on Interstate 84 in Boise, Idaho.
The crash occurred about 11:32 p.m. MDT Saturday, June 16, 2018, when a 2019 Volvo tractor in combination with a 2015 Great Dane refrigerated semitrailer crashed into the end of a traffic queue in a work zone. The 2019 Volvo tractor-trailer collided with a Jeep, which was pushed into the rear of a 2003 Volvo tractor in combination with a 2008 Great Dane refrigerated semitrailer; the 2003 Volvo tractor-trailer moved forward and collided with the rear of a 2006 Ford Fusion, pushing it into the rear of a 2014 Ford F150 and sideswiping a 2015 Ford Escape.
Debris from the collision also damaged a 2010 Ford Focus. The vehicles came to rest on I-84 under the Cloverdale overpass. A post-crash fire consumed the Jeep and the 2003 and 2019 Volvo combination vehicles. The fire also damaged other vehicles and the Cloverdale overpass.
The 42-year-old driver of the 2019 Volvo tractor, along with the driver and two passengers in the Jeep, died as a result of the crash; the driver and passenger of the 2006 Ford Fusion and the driver of the 2014 Ford F150 were injured. The 2019 Volvo tractor was operated by Krujex Freight Transportation Corp.
According to the NTSB’s final report, multiple factors contributed to the crash. The probable cause is noted as the 2019 Volvo tractor driver’s “failure to respond to the slow-moving traffic queue ahead, most likely due to performance decrements associated with fatigue. Contributing to the crash were the (1) inadequate traffic control and queue management procedures employed by Penhall Company and its subcontractor Specialty Construction Supply Company, Inc., and (2) lack of proper oversight by the Idaho Transportation Department, which allowed an additional lane closure that was not part of the approved traffic control plan, resulting in a traffic queue that extended into the advance warning area of the work zone.”
The NTSB’s preliminary report noted that in the area of the accident, the roadway consists of four travel lanes and paved shoulders for both the eastbound and westbound lanes, but that the time of the crash, I-84 east had been reduced from four lanes to one lane about 1 mile beyond the crash location because of an ongoing maintenance project near the Cloverdale overpass. The posted 65-mph speed limit was reduced to 55 mph for the work zone.
According to data obtained from an aftermarket on -board Garmin unit, which recorded vehicle speed, interior audio, and forward-facing video when triggered, the 2019 Volvo was traveling approximately 62 mph at the time of impact with the Jeep.