CODE OF FEDERAL REGULATIONS
TITLE 49 – TRANSPORTATION
PART 571 FEDERAL MOTOR VEHICLE SAFETY STANDARDS
§ 571.209 Standard No. 209; Seat belt assemblies.
S1. Purpose and scope. This standard specifies requirements for seat belt assemblies.
S2. Application. This standard applies to seat belt assemblies for use in passenger cars, multipurpose passenger vehicles, trucks, and buses.
Type 1 seat belt assembly is a lap belt for pelvic restraint.
Type 2 seat belt assembly is a combination of pelvic and upper torso restraints.
S4.1.(e) Release. A Type 1 or Type 2 seat belt assembly shall be provided with a buckle or buckles readily accessible to the occupant to permit his easy and rapid removal from the assembly. Buckle release mechanism shall be designed to minimize the possibility of accidental release. A buckle with release mechanism in the latched position shall have only one opening in which the tongue can be inserted on the end of the buckle designed to receive and latch the tongue. (emphasis added).