(a) Following the first year of noncompliance. An amount up to 4 percent of the Federal-aid highway funds required to be apportioned to any State under 23 U.S.C. 104(b)(1) and (2) shall be withheld from a State on the first day of the fiscal year following such State's first year of noncompliance under this part.

(b) Following second and subsequent year(s) of noncompliance. An amount up to 8 percent of the Federal-aid highway funds required to be apportioned to any State under 23 U.S.C. 104(b)(1) and (2) shall be withheld from a State on the first day of the fiscal year following such State's second or subsequent year(s) of noncompliance under this part.