49 CFR § 350.309 - Compatibility review: Consequences of incompatible provisions.

---
identifier: "/us/cfr/t49/s350.309"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 350.309 - Compatibility review: Consequences of incompatible provisions."
title_number: 49
title_name: "Transportation"
section_number: "350.309"
section_name: "Compatibility review: Consequences of incompatible provisions."
chapter_name: "FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "B"
subchapter_name: "FEDERAL MOTOR CARRIER SAFETY REGULATIONS"
part_number: "350"
part_name: "MOTOR CARRIER SAFETY ASSISTANCE PROGRAM (MCSAP) AND HIGH PRIORITY PROGRAM"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 504, 13902, 31101, 31102, 31104, 31106, 31108, 31136, 31141, 31161, 31310, 31311, 31502; secs. 5106 and 5107, Pub. L. 114-94, 129 Stat. 1312, 1530; and 49 CFR 1.87."
regulatory_source: "85 FR 37796, June 24, 2020, unless otherwise noted."
cfr_part: "350"
---


# 350.309 Compatibility review: Consequences of incompatible provisions.

(a) *General.* To remain eligible for MCSAP funding, a State may not have in effect or enforce any State law, regulation, standard, or order on CMV safety that the Administrator finds is not compatible (as defined in § 350.105).

(b) *Process.* FMCSA may initiate a proceeding to withdraw the current CVSP approval or withhold MCSAP funds in accordance with § 350.231 if:

(1) A State enacts a law, regulation, standard, or order on CMV safety that is not compatible;

(2) A State fails to adopt a new or amended FMCSR or HMR within 3 years of its effective date; or

(3) FMCSA finds, based on its own initiative or on a petition of a State or any person, that a State law, regulation, standard, order, or enforcement practice on CMV safety, in either interstate or intrastate commerce, is not compatible.

(c) *Hazardous materials.* Any decision regarding the compatibility of a State law, regulation, standard, or order on CMV safety with the HMRs that requires an interpretation will be referred to the Pipeline and Hazardous Materials Safety Administration of the United States Department of Transportation before proceeding under § 350.231.