“Decoding” Bus Body Code – AIS 052.

Mercedes Benz SHDMercedes Benz SHD

Former Ministry of Surface Transport now called Ministry of Shipping, Road Transport & Highways, requested the CMVR-Technical Standing Committee to frame requisite guidelines on Standardization of the Bus Body during early 2000. A Sub-Committee was formed under Mr. A. S. Lakra, the then Director Engineering, of ASRTU to look into various aspects concerning Bus Body Design issue by the CMVR Committee. Series of meetings were held to deliberate on the issues and other sub-groups were set-up to deliberate and conclude on the relevant and critical technical issues. The Sub-Committee completed its task and the subject was finally discussed in the 10th CMVR-Technical Standing Committee meeting held on the 5th and 6th of July, 2001. The finalised “ Code of Practice for Bus Body Design and Approval” was submitted to the Ministry for further necessary action. The standard AIS-052 was published in September 2001.

Tata LPO 1512 Bus Structure

Tata LPO 1512 Bus Structure

With now close to 16 years of first release, the standard is yet to be fully implemented for various reasons. Primary reason being the paradigm shift in the way a bus body is recommended to be built by bus body code. Implementing bus body code isn’t a easy job either and it’s now implemented partially and the complete code will be implemented from next year April. Since the discussion started on the bus body code, till now there are seven amendments are released and the latest being on 4th May 2016.

We are  sharing some of the important requirements that are given in bus body code through this article.

Classification of Buses 

Based on application:

1.Type 1 – Commonly used for city application

2.Type 2 – Commonly used for stage carriage application or Inter urban application

3.Type 3 – Commonly used for long distance intercity application

4.Type 4 – Commonly used for school, airport, sleeper, tourist application

NBSTC Ashok Leyland SLF bus procured in JNNURM-2 scheme

Based on comfort:

1.Non Deluxe Bus (NDX)- bus with minimum comfort level, mostly a 3×2 layout

2. Semi Deluxe Bus (SDX) – slightly higher comfort level and with provision for ergonomically designed seats, mostly a 3×2 with high back rest.

3.Deluxe Bus (DLX) – a bus designed for a high comfort level and individual seats and adjustable seat backs, improved ventilation and pleasing interiors, mostly a 2×2 with push back seats.

4.AC Deluxe Bus(ACX) – a Deluxe Bus which is air conditioned


Based on capacity:

1.Low capacity – This is further classified into Micro bus (upto 12 passengers) and Mini bus (upto 22 passengers). Bus code is not applicable to Micro buses.

2.Medium capacity – This is further classified into Midi bus (seating capacity between 23 to 34) and standard bus (seating capacity between 35 to 70)

3.High capacity – Buses with seating capacity more than 70 like Articulated bus, Double decker bus etc

1.Minimum dimension for a door shall be 650mm in width and 1800mm in height. The same can be reduced by 550mm when the measurement is made at the level of the hand holds.

2.Passenger door: The Min of doors is given below and the buses are free to have more than this as well. Mini and Midi buses are exempted from this.

Type 12211
Type 21111
Type 3NA111

3. Windows: The Min window aperture shall be 550mm for standard bus and 450mm for mini and midi bus. This is not applicable for sleeper bus and ACX bus.

4. Guard rails: There should be min 2 guard rails and space between them shall be 75mm to 100mm. This is not applicable to ACX bus.

5. Emergency Exits : There shall be min 1 emergency door and the same shall be located in the opp side of service door (dim 1250mm x 550mm). In case of more than 1 service door, the same shall be given in the front half of vehicle. However windows can also be treated as emergency exits, provided they meet the criteria.

6. Roof hatches: (dim 50cm x 70cm)can also be provided they are located in middle segment of the roof, when the entire roof is considered as three segments. When 2 or more roof hatch is provided there should be min 2 mtrs of distance.

7. Step Dimension: Max height of first step from ground is 340mm for type I and for type II and type III will be 380mm. Other steps height will be 250mm for type I and 350mm for type II and type III.

8. Gang ways : Gangway shall be min 450 mm for type I, 350 mm for type II and 300 mm for type III. Overall internal height shall be min 1900 mm. Gangway can also be provided with a slope.

 9. Seating layout :

Seating layout

10. Seat Width:

The backrest shall have min dimensions of 800 mm for type I, 1000 mm for type II and 1100 for type III.

11. Seat Spacing:

Seating pitch

12. Seat width:

Seating width

13. Destination board:

Destination board

 14.Provision for disabled passengers 

All Type I buses shall have at least two passenger seats in case of Mini & Midi buses and four passenger seats in case of other buses designated as priority seats for persons with disabilities. These seats shall be only of the forward facing type and preferably be located behind the driver’s seat.

15. Other recommendations The recommended features for various types / categories of buses are
given in table below. However, features superior to the ones indicated in this table may also be permitted.


Disclaimer : The article is prepared with the release standard on 14th March 2017. The standard is likely to be updated constantly and hence its requested to check the current level of standard, when references are to be taken. For detailed understanding on testing procedure and requirements, one could check the published standards.

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