On Sunday, September 21, 2014, about 4:15 p.m. local time, a 1996 Setra motorcoach was traveling on State Route 1 (SR-1) in Delaware en route to New York City. The motorcoach was returning from a 2-day tour that originated in New York City, with planned sightseeing stops in New York State, New Jersey, Pennsylvania, Maryland, and Washington, DC. The driver reported being familiar with the planned route. However, while traveling northbound on Interstate 95, he encountered traffic congestion and decided to divert. He took US Route 40 (US-40, Pulaski Highway) northeast to SR-1 south and then entered the curved access ramp to US Route 13 (US-13) north. The driver was unfamiliar with this alternate route and reported using his personal global positioning system (GPS) to navigate.
At the point where the SR-1 access ramp curves sharply to the right, the driver failed to negotiate the curve, and the motorcoach departed the left edge of the roadway. The motorcoach entered an earthen area, rotated clockwise, and overturned onto its left (driver) side and partially onto its roof, coming to rest about 25feet off the roadway. The motorcoach occupants included the 56-year-old driver and 50 passengers. The motorcoach was operated by AM USA Express. Three passengers died as a result of the crash, and the driver and 47 passengers were injured. At the time of the crash, the weather was clear, and the road conditions were dry. The National Transportation Safety Board (NTSB) completed a field investigation of this crash, focusing on highway, vehicle, human performance, and motor carrier factors.