AIS 153 Becomes Mandatory From September 2025: New Safety and Design Rules for Bus Body Builders Explained

India’s bus manufacturing landscape is set for a major overhaul as the amended AIS 153 standards officially come into force from September 2025. The new rulebook—now mandatory for every newly built bus—introduces sweeping changes across structural design, passenger safety, comfort norms, and certification procedures. The move aims to bring uniformity and modernisation to the country’s fragmented bus body-building sector.

Originally applicable only to OEMs producing fully built buses for more than 22 passengers since April 2019, the revised framework now extends to non-OEM bus body builders, making compliance essential for all manufacturers. The standard has been formulated by the Ministry of Road Transport & Highways (MoRTH) under the Central Motor Vehicle Rules (CMVR).

Industry experts say the transition marks a turning point. “AIS 153 ushers in a new era of safety, standardization, and global alignment for Indian buses,” said Shivakumar V, Group Chief Strategy Officer at MG Group. “It strengthens compliance and improves passenger protection.”

What AIS 153 Now Requires

The updated norms introduce detailed instructions for critical areas of bus construction, with particular emphasis on safety, comfort, and technological integration.

Noise, Vibration and Harshness (NVH)

Passenger comfort remains a core focus. The standards set strict interior noise limits—85 dB(A) for front-engine buses and 80 dB(A) for rear-engine models—and prescribe vibration thresholds to ensure smoother rides. Sleeper buses must undergo additional vibration testing at designated berth locations.

Intelligent Transport Systems (ITS)

To enhance fleet management and security, AIS 153 mandates GPS tracking, LED destination boards, driver behaviour monitoring systems, real-time passenger information displays, and CCTV surveillance with 30-day recording. All ITS components must comply with EMI/EMC guidelines under AIS 004.

Fire Safety Requirements

Safety systems differ depending on bus type.
• Seater buses must have Fire Detection Alarm Systems (FDAS) as per AIS 135.
• Sleeper and school buses require Fire Detection and Suppression Systems (FDSS), offering automatic fire control for enhanced protection.

Vehicles under 3.5 tonnes GVW are exempt from mandatory installation.

Emergency Exits and Safety Design

The amendments to AIS 119 lay out clear rules for emergency exits:
• Buses up to 12 metres must have a minimum four exits.
• Longer buses require a minimum five exits, including multiple roof hatches.

Emergency doors must be operable from both inside and outside. The updated regulations also prohibit driver partition doors to prevent obstruction during emergencies.

Lighting Requirements

Driver cabins, passenger compartments, luggage holds, and entry/exit points must meet minimum illumination levels—ranging from 30 to 150 lux at the driver cabin to 50 lux in passenger areas. Exit lamps must automatically illuminate when doors open.

Power-to-Weight Norm

Every bus must maintain a minimum ratio of 5 kW per tonne of gross vehicle weight.

Certification Process

Manufacturers must secure type approval from accredited agencies such as ARAI, ICAT, or CIRT. This involves submitting technical documents, undergoing physical tests, and verifying compliance for each variant.

A Turning Point for the Industry

Industry leaders believe the transition will transform India’s public transport standards. “This is about elevating the travel experience,” said Yash Sharma, Director at Damodar Group. “The new norms will make buses safer, smarter, and more comfortable.”

While compliance may increase costs for manufacturers, AIS 153 is expected to reinforce quality and give Indian bus makers an edge in a rapidly evolving mobility landscape.