On Tuesday, December 17, 2019, about 3:30 p.m. eastern standard time, a sport utility vehicle (SUV) was traveling east on US Highway 76 (US-76) in Belton, South Carolina. The posted speed limit was 45 mph. Meanwhile, a medium-size bus—occupied by a driver and 7 passengers, 2 of whom were seated in wheelchairs—was traveling west on US-76 at a speed of about 45 mph. According to a witness following behind the SUV, it was traveling erratically across the lanes. Shortly before the crash site, the SUV accelerated to a speed of about 75 mph and, about 1–2 seconds before the impact, crossed the center line and subsequently collided with the left side of the bus, intruding into the bus just behind the driver. The unbelted SUV driver was ejected and fatally injured. A lap-belted bus passenger seated in the intrusion area sustained fatal injuries. The remaining bus occupants sustained minor to serious injuries.

​​Leading up to the crash, the driver of the SUV had engaged in a 16-minute phone call with a friend that ended less than a minute before the collision. During that conversation, the SUV driver received two incoming calls that she did not answer. She ended the first phone call and placed a call on her cell phone to the incoming number. The driver’s outgoing call went to voicemail. Following this call, several incoming calls went unanswered.

Cell phone use—including talking and placing or receiving calls while driving—is a nationally recognized cause of driver distraction. Cell phone use may be manually, visually, and cognitively distracting to the driver. Prohibiting the use of cell phones and other portable electronic devices for calls or texting while driving can decrease the number of distracted driving-related crashes. Cell phone technology, such as Do Not Disturb modes, can lessen the distraction of incoming calls or texts to drivers.

During the postcrash examination of the bus, we found that the occupant restraints used to secure the wheelchair occupants were severely twisted. Additionally, postcrash placement of the wheelchairs suggested that they had been improperly secured to the bus. Improper positioning of the wheelchair securement straps and twisting of the webbing of the belt system for the wheelchair occupants can increase their risk of injury.

Further investigation revealed that training in how to secure wheelchairs for transportation had been only a small part of the defensive driving session for the bus driver. Following communication with the NTSB, the bus transportation provider improved its wheelchair securement training. It is critical that drivers and others responsible for securing wheelchairs and their occupants in vehicles do so properly to limit potential injury.

We determined that the probable cause of this crash was the SUV driver’s loss of control of her vehicle due to distraction from cell phone use, resulting in the SUV crossing into the opposite travel lane and colliding with the medium-size bus. Contributing to the severity of the crash was the excessive speed of the SUV.

​​As a result of this investigation, we recommended that the National Association of State Directors of Developmental Disabilities Services inform its members of the circumstances of this crash and advise them to ensure that their employees receive annual training in securing wheelchairs and their occupants for transportation.

We also reiterated a recommendation to the 50 states and the District of Columbia to (1) ban the nonemergency use of portable electronic devices (other than those designed to support the driving task) for all drivers; (2) use the National Highway Traffic Safety Administration model of high visibility enforcement to support these bans; and (3) implement targeted communication campaigns to inform motorists of the new law and enforcement, and to warn them of the dangers associated with the nonemergency use of portable electronic devices while driving.

Finally, we reiterated a recommendation to manufacturers of portable electronic devices (Apple, Google, HTC, Lenovo, LG, Motorola, Nokia, Samsung, and Sony) to develop a distracted driving lock-out mechanism or application for portable electronic devices that will automatically disable any driver-distracting functions when a vehicle is in motion, but that allows the device to be used in an emergency; install the mechanism as a default setting on all new devices and apply it to existing commercially available devices during major software updates.

​We also classified from “Open—Acceptable Response” to “Open—Unacceptable Response” Safety Recommendation H-15-40, which asked the National Highway Traffic Safety Administration to develop, and require compliance with, a side-impact protection standard for all newly manufactured medium-size buses, regardless of weight.