Dolan Springs, Arizona January 30, 2009
NTSB Number: HAR-10-01
NTIS Number: PB2010-916201
On Friday, January 30, 2009, about 4:06 p.m. mountain standard time, a 2007 Chevrolet/Starcraft 29-passenger medium-size bus, operated by DW Tour and Charter and occupied by the driver and 16 passengers, was traveling northbound in the right lane of U.S. Highway 93, a four-lane divided highway, near Dolan Springs, Arizona. The bus was on a return trip from Grand Canyon West to Las Vegas, Nevada, after a day-long tour. As the bus approached milepost 28 at an estimated speed of 70 mph, it moved to the left and out of its lane of travel. The driver steered sharply back to the right, crossing both northbound lanes and entering the right shoulder. The driver subsequently overcorrected to the left, causing the bus to yaw and cross both northbound lanes. The bus then entered the depressed earthen median and overturned 1.25 times before coming to rest on its right side across both southbound lanes. During the rollover sequence, 15 of the 17 occupants (including the driver) were fully or partially ejected. Seven passengers were killed, and nine passengers and the driver received injuries ranging from minor to serious. At the time of the accident, the roadway was dry and the weather was clear.
The National Transportation Safety Board determines that the probable cause of the January 30, 2009, accident near Dolan Springs, Arizona, was the bus driver's inadvertent drift from the driving lane due to distraction caused by his manipulation of the driver's side door and subsequent abrupt steering maneuver, which led to losing directional control of the vehicle. Contributing to the severity of the accident was the lack of both occupant protection and advanced window glazing standards for medium-size buses.
The following safety issues were identified in this investigation:
To the National Highway Traffic Safety Administration:
Require new commercial motor vehicles with a gross vehicle weight rating above 10,000 pounds to be equipped with lane departure warning systems. (H-10-1)
To maintain consistency in bus body classifications and to clarify the scope of bus safety initiatives, develop regulatory definitions and classifications for each of the different bus body types that would apply to all U.S. Department of Transportation agencies and promote use of the definitions among the bus industry and state governments. (H-10-2) (This recommendation supersedes Safety Recommendations H-99-43 and -44 and is classified "Open—Unacceptable Response.")
In your rulemaking to improve motorcoach roof strength, occupant protection, and window glazing standards, include all buses with a gross vehicle weight rating above 10,000 pounds, other than school buses. (H-10-3)
Develop performance standards for all newly manufactured buses with a gross vehicle weight rating above 10,000 pounds to require that overhead luggage racks are constructed and installed to prevent head and neck injuries and remain anchored during an accident sequence. (H-10-4) (This recommendation supersedes Safety Recommendations H-09-23 and -24.)
Develop stability control system performance standards applicable to newly manufactured buses with a gross vehicle weight rating above 10,000 pounds. (H-10-5)
Once the performance standards from Safety Recommendation H-10-5 have been developed, require the installation of stability control systems in all newly manufactured buses in which this technology could have a safety benefit. (H-10-6).
Require that all buses above 10,000 pounds gross vehicle weight rating be equipped with on-board recording systems that: (1) record vehicle parameters, including, at minimum, lateral acceleration, longitudinal acceleration, vertical acceleration, heading, vehicle speed, engine speed, driver's seat belt status, braking input, steering input, gear selection, turn signal status (left/right), brake light status (on/off), head/tail light status (on/off), passenger door status (open/closed), emergency door status (open/closed), hazard light status (on/off), brake system status (normal/warning), and flashing red light status (on/off; school buses only); (2) record status of additional seat belts, airbag deployment criteria, airbag deployment time, and airbag deployment energy; capable of preserving data in the event of a vehicle crash or an electrical power loss; and (4) are mounted to the bus body, not the chassis, to ensure recording of the necessary data to define bus body motion. (H-10-7) (This recommendation supersedes Safety Recommendation H-99-53 and is classified "Open—Unacceptable Response.")
The National Transportation Safety Board classifies the following previously issued recommendations: