AIS 153 Explained: New Bus Body Rules India

From September 2025, India’s bus manufacturing industry will operate under a significantly revised regulatory framework as the amended AIS 153 standards become mandatory. The new norms are set to bring uniformity, higher safety benchmarks, and improved passenger comfort across all buses built in the country, marking a decisive shift in how bus bodies are designed and approved.

What Is AIS 153 and Why It Matters

AIS 153 is an Automotive Industry Standard notified by the Ministry of Road Transport and Highways under the Central Motor Vehicle Rules. It defines detailed guidelines for bus body design, construction quality, and safety systems. While OEMs have been complying with AIS 153 since April 1, 2019, the next phase will extend these requirements to non-OEM bus body builders, ensuring industry-wide standardization.

Industry experts view this amendment as a major modernization step that aligns Indian bus manufacturing with global safety and design practices.

Focus on Intercity and Large Buses

The updated norms primarily target intercity buses, especially vehicles measuring 12 meters and above. These buses form a critical part of long-distance and high-capacity transport, making safety, comfort, and structural integrity essential. The amendments clarify certification requirements specifically for this category to remove ambiguity for body builders.

Stricter Noise, Vibration, and Harshness Limits

Passenger comfort is a central theme of AIS 153. Interior noise levels are capped at 85 dB(A) for front-engine buses and 80 dB(A) for rear-engine buses. Structural vibration limits and harshness thresholds have been introduced to minimize fatigue and discomfort during long journeys. Sleeper buses are subject to additional vibration measurement protocols to ensure acceptable comfort levels while passengers are resting.

Mandatory Intelligent Transport Systems

AIS 153 introduces compulsory Intelligent Transport Systems to improve safety and fleet monitoring. Buses must be equipped with GPS tracking, LED destination boards, real-time passenger information displays, driver behavior monitoring systems, and CCTV cameras with at least 30 days of recording storage. All electronic systems must comply with electromagnetic compatibility norms to avoid interference.

Enhanced Fire Safety Requirements

Fire safety norms have been significantly strengthened under the amended standard. Seater buses must be fitted with Fire Detection Alarm Systems, while sleeper and school buses require Fire Detection and Suppression Systems. These systems are designed to detect smoke, heat, or carbon monoxide early and either alert occupants or automatically suppress fires to reduce evacuation risks.

Revised Emergency Exit Norms

Emergency exit regulations now vary based on bus length. Buses up to 12 meters must have a minimum of four emergency exits, while buses exceeding 12 meters require at least five. The rules clearly define the placement of emergency doors and roof-mounted escape hatches. Notably, driver partition doors are no longer permitted, as they may obstruct passenger movement during emergencies.

Lighting and Power Requirements

AIS 153 mandates adequate lighting in driver cabins, passenger compartments, luggage holds, and exits to ensure visibility at all times. The standard also specifies a minimum engine or electric motor power-to-gross vehicle weight ratio of more than 5 kW per ton, ensuring adequate performance and safety margins.

Certification and Type Approval Process

To comply with AIS 153, bus body builders must obtain type approval from accredited agencies such as ARAI, ICAT, or CIRT. This involves submitting technical documentation and undergoing physical safety and performance tests. The issued type approval certificate is mandatory for vehicle registration.

A Turning Point for the Bus Industry

The amended AIS 153 standards go beyond regulatory compliance. They represent a shift toward safer, smarter, and more passenger-focused buses in India, compelling manufacturers to upgrade design practices, adopt advanced safety systems, and align with higher national and global expectations.