On Friday, September 20, 2019, about 11:30 a.m. mountain daylight time, a 2017 medium-size bus was traveling east on Utah State Route 12 (SR-12), a two-lane highway, near Bryce Canyon City in Garfield County, Utah. The posted speed limit was 65 mph, and the weather was clear and dry. The bus, which was operated by the motor carrier America Shengjia, was occupied by a 60-year-old driver and 30 passengers. The bus was carrying passengers on a tour that originated in Los Angeles, California, and was scheduled to end in Salt Lake City, Utah, on September 20. Bryce Canyon was the last stop before Salt Lake City.
Near mile marker 10.4 on SR-12, at a vehicle-recorded speed of about 64 mph, the bus’s right wheels departed the right edge of the roadway. The driver steered left to return the bus to the roadway, a maneuver that redirected the bus into the westbound travel lane. The driver then steered sharply to the right, causing the bus to become unstable. It then rolled 90 degrees, or a quarter turn, onto its left side. The bus slid on its left side for about 85 feet, until its roof struck the guardrail end treatment along the side of the westbound roadway and rolled over the guardrail, coming to rest on its wheels after one complete roll. At final rest, the bus straddled the damaged guardrail, with its front end partially blocking the westbound travel lane of SR-12. No other vehicles were involved in the crash.
As a result of the crash, 4 passengers were fatally injured, 17 sustained serious injuries, and 9 sustained minor injuries. Thirteen passengers were either fully or partially ejected from the bus during the crash sequence. The bus driver was not injured. All rear seating positions were equipped with lap belts, and the driver and front passenger seats were equipped with lap/shoulder belts.
The probable cause of the Bryce Canyon City, Utah, crash was the bus driver’s failure, for undetermined reasons, to maintain the bus within its travel lane and his subsequent steering overcorrections, which caused the bus to become unstable and roll over. Contributing to the severity of the crash was the roof’s deformation, caused by the rollover, and its further collapse upon impact with the guardrail, which created ejection portals and compromised the survival space of the passenger seating compartment. Also contributing to the severity of the crash was the National Highway Traffic Safety Administration’s failure to develop and promulgate standards for bus roof strength and window glazing to enhance the protection of bus passengers. Contributing to the ejections and the severity of the injuries was the lack of passenger lap/shoulder belts on the bus.