A detailed investigation report into the "4·26" major road transport accident on the Haikou-Sanya Expressway in Tunchang County was officially released on September 15 by the Hainan Provincial Department of Emergency Management. The report disclosed that at approximately 4:32 AM on April 26, 2026, a serious traffic collision occurred at the 59-kilometer mark of the G9811 Haikou-Sanya Expressway within Tunchang County's jurisdiction, involving a small passenger vehicle and a heavy curtain-side truck, which tragically resulted in five fatalities.

Following the incident, on May 9, 2026, the Hainan Provincial Government established a dedicated investigation team for the "4·26" accident, led by the Provincial Department of Emergency Management and comprising representatives from the Public Security Department, the Department of Tourism, Culture, Radio, Television and Sports, the Department of Transport, the Department of Justice, the Provincial Federation of Trade Unions, the Tunchang County Government, and the Wuzhishan City Government. The Provincial People's Procuratorate was also invited to participate in the investigation proceedings. The official investigation concluded that this major road transport production safety liability accident was collectively triggered by a combination of serious overloading of the truck, distracted driving by the operator, failure to set up proper warning signs following the initial crash, coupled with illegal passenger transport operations and multiple gaps in safety supervision across various levels.

Sequence of the Collision: A Chain Reaction on the Expressway

According to the investigation findings, at approximately 4:24 AM on April 26, 2026, a driver identified as Liu, operating a heavy box-type truck with the license plate Wan SG2779, was traveling southbound on the expressway. Due to distracted driving, Liu's vehicle rear-ended a low-speed passenger car with the plate Qiong ADM2932. As a result of the impact, compounded by the truck's severe overloading and improper handling, the vehicle lost control and overturned, collapsing the central median barrier and invading the opposing northbound carriageway, coming to a halt while blocking the emergency lane and the slow lane. Immediately following this, a heavy curtain-side truck with the plate Gui KW2878, driven by a person named Mo Xihui and traveling northbound, collided with the overturned vehicle. This secondary impact left the Gui KW2878 truck damaged and stopped within the driving lane approximately one hundred meters north of the initial incident site, straddling the lane divider between the left and right driving lanes.

Then, at approximately 4:32 AM on the same day, a driver designated as Chen Xibo, operating a small ordinary passenger vehicle with the plate Hei B0B808, was traveling northbound along the same stretch. Chen's vehicle rear-ended the stationary Gui KW2878 truck on the roadway. This final collision resulted in the deaths of five occupants inside the small passenger vehicle: Chen Xibo, Li, Wang, Su, and Liu.

Root Cause Analysis: Distracted Driving and Failure to Set Up Warnings

The investigation report identified the direct cause of the accident as the actions of Chen Xibo, who was driving the Hei B0B808 small passenger vehicle that did not meet technical safety standards. While navigating the expressway, Chen was distracted and failed to adequately observe the road conditions ahead, preventing him from detecting the dangerous situation in time and taking effective evasive measures. Concurrently, Mo Xihui, who was driving the non-compliant Gui KW2878 heavy truck, stopped his vehicle across two lanes of the expressway after the initial collision without promptly setting up warning signs or extending a safe warning distance as required by regulations. Additionally, Liu, driving the severely overloaded Wan SG2779 box truck, was distracted, leading to his vehicle overturning into the opposing lanes, occupying the emergency lane and part of the slow lane. He also failed to extricate himself from the overturned cab in a timely manner and fulfill his legal obligation to set up warning markers.

The official "Road Traffic Accident Determination Letter" issued by the Traffic Management Brigade of the Tunchang County Public Security Bureau determined that Chen Xibo and Mo Xihui bear primary responsibility for the accident, while Liu holds secondary responsibility. The investigation also identified profound indirect causes. Notably, Chen Xibo lacked the required "Road Transport Practitioner Qualification Certificate" and was operating the Hei B0B808 vehicle, which itself did not possess a valid "Road Transport Certificate," using it for long-term commercial passenger transport without authorization. Furthermore, the freight company that owned the Wan SG2779 truck, Bozhou Deli Logistics Co., Ltd., failed to implement full-lifecycle safety management responsibilities for its affiliated vehicles, allowing the truck to operate on the road with expired operational qualifications. Additionally, Taihe County Nanfang Logistics Co., Ltd., the enterprise involved, neglected source control over loading, permitting the Wan SG2779 truck to leave its premises with illegal overloading. Local transportation and comprehensive law enforcement departments also had supervisory loopholes in areas such as illegal passenger transport, cargo transportation management, road enforcement, and source-level overload control, with inadequate safety oversight enforcement that laid the groundwork for this tragedy.

Accountability: Criminal Liability and Administrative Sanctions

The investigation report detailed the accountability measures. Chen Xibo, the driver of the black passenger car, and Mo Xihui, the driver of the heavy truck, were both identified as bearing primary responsibility for the accident and are suspected of constituting the crime of causing a traffic accident. Since Chen Xibo perished in the crash, he will not be referred for criminal prosecution. However, it is recommended that Mo Xihui be transferred to the public security authorities for suspected traffic accident crimes. Additionally, four responsible individuals from the Wuzhishan City Bureau of Natural Resources, Planning and Urban-Rural Construction and the Wuzhishan City Comprehensive Administrative Law Enforcement Bureau have been transferred to discipline inspection and supervision agencies for handling. The investigation team also recommended that the Wuzhishan City Party Committee, the Wuzhishan City Government, and the Hainan Provincial Department of Transport be required to submit written self-examinations to the Hainan Provincial Party Committee and the Provincial Government regarding the issues exposed by this incident.