Why are sleeper buses prone to infernos

The high casualties in these incidents have brought renewed attention to the safety of sleeper buses operating on India’s highways

Unlike original equipment manufacturers that use multiplex wiring to distribute electrical load safely, local bus body builders often rely on cheaper components sourced from informal markets. “When wires overheat, insulation burns, sparking begins and once fire enters the wiring network, it spreads through the entire bus in minutes,” he said.

Experts said that many sleeper buses involved in fires are not factory built sleepers but standard coaches retrofitted locally after their registration. (HT Photo)

Chikkara said hammers to break the glass panels during emergency and fire alarm and suppressor systems are also not usually provided in buses customised by local body builders.

Other than the wiring, what turns such fires into mass fatality events is the sleeper coach layout itself. Narrow aisles, stacked berths and limited headroom severely restrict movement during emergencies. Technically, sleeper buses are required to have multiple emergency exits, but in practice rear exits are often blocked after registration to add extra berths in many of the custom built buses.

“In a fire, passengers then have to crawl through several compartments to reach an escape point. If there is no space to stand or move, escape becomes impossible,” said Aditya Rane, senior associate at ITDP India, which provides knowledge support to bus operators.

In India, the Automotive Industry Standards such as AIS-052 (bus body code), AIS-119 (sleeper bus code) and AIS-134 (fire detection and suppression systems) lay down requirements for construction and fire safety.

But, SN Dhole, head of technical secretariat at Central Institute of Road Transport (CIRT), said enforcement has failed to keep pace. “Standards exist, but compliance is largely document-based,” he said.

“Local body builders often use parts that cannot withstand sustained heat and electrical load while materials such as flammable materials, such as foam, which should be avoided are used, adding the risk profile,” he added.

A key regulatory shift between 2022 and 2024 allowed accredited body builders to self-certify. Routine physical inspections by Regional Transport Offices (RTOs) were diluted, with authorities relying increasingly on uploaded certificates. But, Dhole said even though this rule was reversed, the flaws go undetected or ignored.

RTOs are expected to issue fitness certificates every two years and flag malpractices in vehicle design. “There is an acute shortage of trained engineers who can actually assess electrical systems and fire safety. In many states, clerical staff have been assigned inspection duties because technical posts remain vacant,” explained Chhikara.

Gurmit Singh, another office-bearer of BOCI, flagged another common feature in the current scheme of things. “Often vehicles are registered in Arunachal Pradesh or Nagaland, and they are not subjected to real physical fitness tests and operate thousands of kilometres away with minimal oversight.”

He said, in light of these recent incidents, the Union road transport ministry during a stakeholder meeting, had mulled putting a blanket ban on customised sleeper buses in favour of only OEM-made coaches.

Incidentally, China had banned sales of all types of sleeper buses after some fatal accidents in 2012.

The victims of the recent bus fires were passengers with limited choices.

“These are typically people who cannot afford premium buses and are unable to get confirmed train tickets, especially on long-distance routes. They travel overnight, trusting that the bus is safe,” said Madhu Sudan Sharma, senior programme officer at Consumer Unity and Trust Society and member of the Road Safety Network from Rajasthan. The state had seen the maximum number of fatalities, according to the Union government figures tabled in the Parliament.

Sharma said it is only in light of the recent tragedies that the Rajasthan transport department has begun tightening checks on private operators and body builders, focusing on fitness, fire safety systems and unauthorised modifications. He said sustained enforcement would be critical to prevent repeat incidents.

(This report was originally published in December 2025. It has been updated to reflect the Greater Noida incident.)