49 U.S.C. § 30124

Nonuse of safety belts

A motor vehicle safety standard prescribed under this chapter may not require a manufacturer to comply with the standard by using a safety belt interlock designed to prevent starting or operating a motor vehicle if an occupant is not using a safety belt.

( Pub. L. 103–272, § 1(e) , July 5, 1994 , 108 Stat. 957 ; Pub. L. 112–141, div. C, title I, § 31202(a)(2) , July 6, 2012 , 126 Stat. 757 .)