Why the rear seatbelt reminder mandate is just not good enough

I can find very few mass-market cars that actually have rear occupant detection.

BHPian ron178 recently shared this with other enthusiasts:

India can be very thankful to AIS-145, the regulation that has been amended time and again to make sure our cars have driver airbags, front seatbelt reminders, speed alerts, front passenger airbags and more.

Last year, a draft notification was announced to amend it to require require seat belt reminders for the rear seats starting April 2025. I don't know what the status of its implementation in the CMVR is — perhaps BHPians working in the vendor industry can confirm — but the 6th amendment is out on ARAI's website.

AMENDMENT NO. 6* (03/2023) TO AIS-145 Additional Safety features for Category M and N Vehicles

What the new regulation will require

• For a few seconds after you start a trip, the car has to flash the rear seatbelt reminder icon(s) in the dash/cluster, unless:

(a) None of the safety-belts which triggered the warning are unfastened; or
(b) The seat or seats which triggered the warning are no longer occupied.

• When your car is "on the move"*, it must beep/chime and light up, if: (2.2.4.1, 2.2.3.3) (*see 2.2.4.1.1-2.2.4.1.3 of the regulation to see what counts)

The second level warning shall be activated when a safety-belt is or becomes unfastened while the vehicle is in normal operation

• Unless: (2.2.4.3)

(a) None of the safety-belts which triggered the warning are unfastened;
(b) The vehicle ceases to be in normal operation; or
(c) The seat or seats which triggered the warning are no longer occupied.

The silly Maruti-type reminders: still legal!

You might recall the bizarre behaviour of the rear seatbelt reminders on the Maruti Fronx and Jimny. If a rear seatbelt is unfastened, they will beep or chime even if the seat is unoccupied. It looks like it goes beyond Maruti, I see posts around the forum showing even Punch.ev and Astorowners are affected, and I know that a professor of mine has an MG Comet with the same behaviour.

But:

• the regulation allows cars to start beeping simply if a belt is not fastened
• it allows — but doesn't require — the signal to stop if the seat is occupied (note the highlighted "or")

That means this implementation can be perfectly legaleven when the regulation comes into force, so if you were hoping the new regulation would finally put an end to the madness, you're out of luck.

Some cars won't beep when they should

Many other cars won't even beep if the seat is occupied and the belt is not buckled. This is the kind of behaviour in other cars like Toyotas and Hyundais.

They only beep if you're already buckled up and unfasten the belt when you're above ~15-20 km/h, because the regulation says this:

when a safety-belt is or becomes unfastened while the vehicle is in normal operation

...which, apparently, seems to mean the manufacturer has the choice.

And the consumer tests

You would think that since NCAP tests usually go "above and beyond" regulations, they would at least incentivise rear occupant detection, if not flat out require it for a good score.

Over in Europe, that is the case. Even though the EU's new GSR II regulations also allow seatbelt reminders without occupant detection, Euro NCAP does not award them any points. Here is what they had to say about the new Duster and Swift:

A seatbelt reminder system is fitted as standard to the front and rear seats. However, the Duster has no occupant detection system in the rear seats, a prerequisite for scoring, so no points were awarded for the seatbelt reminder.

However, BNCAP does not even evaluate seatbelt reminders, and Global NCAP, who will continue to test cars on request, is using a 12-year-old Euro NCAP protocol to judge seatbelt reminders, and hence:

Rear seat occupant detection is not required but it is recommended.

Link to pdf

Case in point: the Dzire gets the same 1 point for rear seatbelt reminders as the Nexon which actually has occupant detection.

With no regulation or incentive for the better reminders, I think it's very likely we will be left with many cars whose seatbelt reminders are — IMHO — either so benign they don't work, or so annoying you have no option but to disable them. I can find very few mass-market cars that actually have rear occupant detection. VWs, Tatas (Nexon and above), newer Mahindras and BYD ATTO 3 to name a few, but most manufacturers use the cheaper first or second kind.

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