PETALING JAYA: Excessive speed was the primary cause of the June 9 bus crash that killed 15 Universiti Pendidikan Sultan Idris (UPSI) students, according to a preliminary investigation report released by the Ministry of Transport (MOT) today.
The report confirmed the ill-fated bus was travelling at 117 km/h — nearly double the 60 km/h speed limit on the East–West Highway near Tasik Banding — when it overturned and crashed.
“Kinematic analysis showed the vehicle exceeded the safe cornering threshold of around 111.3 to 114.5 km/h,” the report stated.
“The driver lost control, causing the bus to skid and overturn to the left, where it struck a W-beam guardrail that pierced the cabin, resulting in severe injuries and fatalities.”
Although the driver claimed a brake failure, investigators found no evidence of a technical malfunction.
Preliminary inspections did show signs of possible brake overheating, but this may have resulted from excessive or improper brake use. A full technical evaluation will be included in the final report.
In a troubling revelation, the investigation also uncovered serious violations involving both drivers.
One, a 53-year-old designated backup driver, held a Group E licence that had expired in 1998.
The main driver, aged 39, held a valid PSV licence and was behind the wheel at the time.
Both drivers had prior traffic summonses, including for speeding, although the report did not confirm whether these were directly linked to the crash.
The report also highlighted the absence of key safety technologies, such as a Speed Limiting Device (SLD) or active GPS tracking, which could have enabled real-time monitoring and potentially prevented excessive speeding.
Structural weaknesses of the bus further worsened the outcome.
Investigators noted the lack of seat belts and poor roof integrity contributed to the high number of casualties.
“The penetration of the guardrail into the cabin’s main impact zone — where most victims were seated — was a critical factor in the severity of the injuries,” the report said.
As for infrastructure, road surface conditions were found to be within acceptable safety standards, with no indication of adverse weather at the time of the crash.
The road is classified as Category R3, with a maximum speed limit of 60 km/h.
However, investigators uncovered troubling patterns of illegal operations and regulatory non-compliance.
“The operator was found to have committed offences under the Land Public Transport Act 2010,
including the use of unauthorised drivers and manipulation of licensing documentation.
“The Land Public Transport Agency has pledged enforcement action based on these findings. Stern action will be taken against any operator who fails to meet legal and safety requirements.”
In a statement released alongside the report, MOT said the report was tabled at the Cabinet meeting this morning and is being made public in the interest of transparency and public awareness.
MOT added that the report was independently and impartially compiled by a Special Task Force, led by the Chief Inspector of Air Accidents at the MOT, with input from technical experts and representatives from relevant agencies.
It also clarified that the investigation focused solely on safety-related factors and does not interfere with any ongoing criminal investigations by law enforcement.
