Executive Summary: NHTSA final rule, 49 CFR Part 571, Docket No. NHTSA-2024-0071

Executive summary of:
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
NHTSA final rule, 49 CFR Part 571, Docket No. NHTSA-2024-0071

NHTSA is mandating enhanced seat belt reminder systems for both front and rear seats in a wide range of vehicles. The new requirements apply to passenger cars, multipurpose passenger vehicles, trucks, and buses (except for school buses), with a gross vehicle weight rating up to 10,000 pounds. The new law applies to new vehicles only.

What is the timing?

• 9/1/26 is the compliance date for front seats
• 9/1/27 is the compliance date for rear seats
• Multi-stage manufacturers and alterers would have an additional year to comply.

For Front Seats (Driver and Co-Pilot):

• The rule extends and updates seat belt warning requirements for the driver and front passenger seats. The law ensures these warnings are more persistent and noticeable.
• The new law includes both visual and audible alerts for a longer duration to encourage seat belt use.
• These enhancements must be met by September 1, 2026.
• This final rule requires a seat belt warning for both the Driver and Co-Pilot. It excludes a center seat (if there is one).
• Currently, only the driver’s seat is required to have a seat belt warning.

What actually is required?

• The final rule requires a longer-duration audio-visual warning than is currently only required for the driver’s seat belt. A visual warning and a two-phase audible warning are required that is based, in part, on vehicle speed.
  • Visual warning must be visible to the driver. A visual warning is activated and remains active whenever:
    • The ignition switch is in the “on” or “start” position (or the propulsion system is activated)
    • The seat is occupied, and the seat belt is not in use. The warning
  • Audible warning. A two-phase audible warning is required.
    • The first phase warning must activate when the ignition/propulsion system is activated, the seat is occupied, and the belt is not in use.
    • The first phase warning must last for at least 30 seconds, unless the seat belt that triggered the warning is fastened or the second phase audible warning is activated within that time.
    • The second phase audible warning must activate, and remain active, whenever the seat is occupied, the seat belt is not in use, and the vehicle speed is at least 10 km/h (6.2 mph). The audible warning may be temporarily paused to allow another audible safety warning alerting the driver to take immediate action.

For Rear Seats (All seats behind the Driver and Co-Pilot):

• The rule establishes seat belt warning requirements rear passenger seats.
• The new law includes both visual and audible alerts to encourage seat belt use.
• These requirements must be met by September 1, 2027.

What actually is required?

• The final rule requires all vehicle manufacturers to install rear-seat seat belt warning systems. These systems will include:
  • Visual warning must be visible to the driver.
    • The warning must be displayed on vehicle start-up to inform the driver of the status of the rear seat belts and how many or which rear seat belts are in use and/or not in use.
    • The warning must activate when the ignition (or, for electric vehicles (EVs), propulsion system) is activated, and last for at least 60 seconds.
    • No visual warning is required if the system can determine that there are no occupied rear seats or if there are no occupied rear seats with a seat belt that is not in use.
  • Audio-visual change-of-status warning.
    • The final rule requires an audio-visual warning whenever a fastened rear seat belt is unfastened while the vehicle is in forward or reverse drive mode. (The warning is not required if the system can determine that a rear passenger has unfastened the seat belt to exit the vehicle or switch seats).
    • The warning must last for at least 30 seconds or until the seat belt that triggered the warning is re-fastened. The audible portion of the warning may be temporarily paused to allow another audible safety warning alerting the driver to take immediate action.

Requirements related to electrical connections.

• Readily removable rear seats must either automatically establish the electrical connections when the seat is put in place or, if a manual connection is required, the connectors must be readily accessible. Vehicles equipped with certain types of seat belt warning systems are additionally required to provide a visual warning to the driver if a proper electrical connection has not been established.

Telltale location. Visual warning signals need to be visible only to the driver.

Applicability:

• The rule applies to passenger cars, trucks, most buses, and multipurpose passenger vehicles with a gross vehicle weight rating of 4,536 kilograms (10,000 pounds) or less. It does not apply to vehicles like ambulances or certain buses not designed for carrying passengers.
  • A multi-passenger vehicle is a vehicle that can transport more than five people.
  • A bus is a motor vehicle that can carry more than 10 people.
  • School buses are not included in this ruling.

Occupant detection and what constitutes an occupant (passenger) for compliance?
The ruling does not include a requirement for occupant detection. However, if a manufacture voluntarily chooses to equip the vehicle with occupant detection, they can use either of the following to define an occupied rear designated seating position for the purposes of testing the rear seat belt reminder system:

• An anthropomorphic test device at least as large as a 49 CFR part 572, subpart N 6-year-old child dummy or
• A person that is at least 21 kg in weight and 114 cm in height.

FAQ’s

My bus is 10,000 lbs. or greater GVWR. Is a monitoring system required?
The answer is no. However, we believe it is prudent to know if your passengers are properly buckled up.

What about accommodations for securing child seats?
A CRS detection requirement is not part of the final rule. It is recommended that the seat belt be fastened behind the CRS for those that are installed using Lower Anchors and Tethers for Children (LATCH).

Do older buses need to be retrofitted?
No, they do not. You mayhowever do this voluntarily.

My vehicle is part of a “transit system”, do I need seat belt monitoring?
Yes, unless the vehicle is 10,000 lbs. or greater or is a school bus.

Do “limo” or aisle facing vehicle need to have seat belt monitoring?
There appears to be no exemption for limo or aisle facing vehicles.

Sources:
NHTSA Finalizes Seat Belt Reminder Rule to Increase Seat Belt Use, Improve Occupant Safety (Press Release)
Final Rule | Seat Belt Use Warning System for Rear Seats (PDF)

The descriptions and summary provided in this document have been prepared for use as a ready reference and do not have legal force or effect. Always refer to the Federal Motor Vehicle Safety Standards (FMVSS) within the Code of Federal Regulations (CFR), which is established, prescribed, and enforced by the National Highway Traffic Safety Administration (NHTSA).