A train collision involved four negligence factors; a modified bus was suspected as the fire's cause. The "Thai Bus Page" analyzed that the gas tank installed under the bus, beneath the passenger seats, ignited rapidly when struck mid-body.
Aphisit Mantri, the administrator of the Thai Bus Page, analyzed the tragic incident where a train collided with a bus stalled on the tracks to Thairath Online's special news team. He said the main problem is "Thai people's traffic discipline," noting this is not the first such case. Basic traffic rules dictate that vehicles should keep clear at marked lines during congestion, but Thai drivers often queue onto the railway crossing, causing vehicles to be stuck on the tracks. He noted the following observations.
1. Initial inquiries with bus staff, according to the Thai Bus Page and Bus Zone 3, found that both the driver and conductor survived. At the time of collision, the conductor was seated in the front monk seat and was thrown out along with the front bus sign, which some reports mistakenly identified as route 23, though it was route 206. The driver is currently hospitalized. 2. The bus became stuck on the tracks due to traffic congestion; when the bus stopped, other vehicles cut in, prompting the bus to follow and eventually stall on the railway.
3. Regarding signal and crossing barrier abnormalities, at the time of the incident, the railway crossing barrier did not lower, and no flashing lights or usual warning signals were active.
4. Besides the incident site, other high-risk railway crossing points in Bangkok include Ratchaprarop intersection near the Indra Hotel heading toward Sri Ayutthaya, Phaya Thai intersection, and the entire Yommarat area.
The bus hit by the train was modified from its original diesel engine to use NGV gas, in line with environmental policies. A total of 323 buses were converted.
Importantly, the gas tank's position likely caused the rapid fire. This bus model places the gas tank under the vehicle floor beneath the passenger seats from mid-vehicle to the rear wheels. When struck mid-body, this caused an explosion and rapid fire, unlike newer buses which have gas tanks mounted on the roof.
These gases, when leaking, tend to settle low. When mixed with sparks from metal-on-metal contact, such as between vehicles or motorcycles, intense fires resembling a "sea of flames" can occur.
Currently, the Department of Land Transport has a policy not to renew registration for buses equipped with NGV gas tanks after 2028. The Bangkok Mass Transit Authority plans to lease new buses as replacements.
This modification is seen as highly risky for safety in accidents because the gas tank is positioned in a direct impact zone and close to the passenger compartment.
BMTA bus management is often constrained by government policies, preventing selection of the best quality vehicles, with changes tied to political shifts.
Regarding railway safety, better coordination is needed between BMTA and the State Railway of Thailand. The use of sliding grill barriers that fully close is recommended to prevent motorcycles from bypassing the barriers.
This accident is highly significant, especially for public transport passengers. Beyond ensuring drivers adhere to traffic laws, vehicles themselves should be safer. Train drivers might also be unfamiliar with this route, as trains here usually slow down to watch for crossing vehicles moving slowly.