# National Hazardous Materials Route Registry
**AGENCY:**
Federal Motor Carrier Safety Administration (FMCSA), Department of Transportation (DOT).
**ACTION:**
Notice; revisions to the listing of designated and restricted routes for hazardous materials.
**SUMMARY:**
This notice provides revisions to the National Hazardous Materials Route Registry (NHMRR) reported to FMCSA from April 1, 2024, through March 31, 2025. The NHMRR is a listing, as reported by State and Tribal governments, of all designated and restricted roads and preferred highway routes for transportation of highway route-controlled quantities of Class 7 radioactive materials (HRCQ/RAM) and non-radioactive hazardous materials (NRHM).
**DATES:**
*Effective date:* December 8, 2025.
**FOR FURTHER INFORMATION CONTACT:**
Ms. Melissa Williams, Hazardous Materials Division, Office of Enforcement and Compliance, FMCSA, 1200 New Jersey Ave. SE, Washington, DC 20590, (202) 366-4163, *[email protected].* Office hours are from 9 a.m. to 5 p.m., ET, Monday through Friday, except for Federal holidays.
**Legal Basis and Background**
Paragraphs (a)(2) and (b) of section 5112 of title 49 United States Code (U.S.C.) permit States and Tribal governments to designate and limit highway routes over which hazardous materials (HM) may be transported, provided the State or Tribal government complies with standards prescribed by the Secretary of Transportation (the Secretary) and meets publication requirements in section 5112(c). To establish standards under paragraph (b), the Secretary must consult with the States, and, under section 5112(c), coordinate with the States to “update and publish periodically” a list of currently effective HM highway routing designations and restrictions. The requirements that State and Tribal governments must follow to establish, maintain, or enforce routing designations for the transport of placardable quantities of NRHM are set forth in 49 CFR part 397, subpart C. Subpart D of part 397 sets out the requirements for designating preferred routes for HRCQ/RAM shipments as an alternative, or in addition, to Interstate System highways. For HRCQ/RAM shipments, § 397.101 defines a *preferred route* as an interstate highway for which no alternative route is designated by the State; a route specifically designated by the State; or both (see § 397.65 for the definitions of *NRHM* and *routing designations* ).
Under a delegation from the Secretary, [^1] FMCSA has authority to implement 49 U.S.C. 5112.
[^1] 49 CFR 1.87(d)(2).
Currently, § 397.73 establishes public information and reporting requirements for NRHM. States or Tribal governments are required to furnish information regarding any new or changed routes to FMCSA within 60 days after establishment. Under § 397.103, a state routing designation for HRCQ/RAM routes (preferred routes) as an alternative, or in addition, to an Interstate System highway, is effective when the authorized routing agency provides FMCSA with written notification, FMCSA acknowledges receipt in writing, and the route is published in FMCSA's NHMRR. The Office of Management and Budget has approved these collections of information under control number 2126-0014, Transportation of Hazardous Materials, Highway Routing.
In this notice, FMCSA is merely performing the ministerial function of updating and publishing the NHMRR based on input from its State and Tribal partners under 49 U.S.C. 5112(c)(1). Accordingly, this notice serves only to provide the most recent revisions to the NHMRR; it does not establish any new public information and reporting requirements.
**Updates to the NHMRR**
FMCSA published the full NHMRR in a *Federal Register* notice on April 29, 2015 (80 FR 23859). Since publication of the 2015 notice, FMCSA has published seven updates to the NHMRR in *Federal Register* notices on August 8, 2016 (81 FR 52518), August 9, 2018 (83 FR 39500), September 24, 2019 (84 FR 50098), June 3, 2020 (84 FR 34284), June 17, 2021 (86 FR 32306), May 11, 2022 (87 FR 28859), and July 16, 2024 (89 FR 57987).
This notice provides revisions to the NHMRR, reported to FMCSA from April 1, 2024, through March 31, 2025. The revisions to the NHMRR listings in this notice supersede and replace corresponding NHMRR listings published in the April 29, 2015, notice and corresponding revisions to the NHMRR listings published in the August 8, 2016, August 9, 2018, September 24, 2019, June 3, 2020, June 17, 2021, May 11, 2022, and July 16, 2024, notices. Continue to refer to the April 29, 2015, notice for additional background on the NHMRR and the August 8, 2016, notice for the procedures for State and Tribal government routing agencies to update their Route Registry listings and contact information.
The full current NHMRR for each State is posted on FMCSA's website at: *https://www.fmcsa.dot.gov/regulations/hazardous-materials/national-hazardous-materials-route-registry.*
**Revisions to the NHMRR in This Notice**
In accordance with the requirements of §§ 397.73 and 397.103, the NHMRR is revised as follows:
**Table 2—District of Columbia—Designated NRHM Routes**
A new Route Order Designator “C” added and assigned a “0” restriction.
**Table 3—Michigan—Restricted NRHM Routes**
Route Order Designator “A” was updated and now classes 1, 6.2, and 7 are restricted on the Ambassador Bridge.
**Table 4—California—Designated HRCQ RAM Routes**
Route Order Designator “O” was added and assigned a “P” designation.
Route Order Designator “P” was added and assigned a “P” designation.
**Route Order Key**
Each listing in the NHMRR includes codes to identify each route designation and each route restriction reported by the State. Designation codes identify the routes along which a driver may or must transport specified HM. Among the designation codes is one for preferred routes, which apply to the transportation of HRCQ/RAM. Restriction codes identify the routes along which a driver may not transport specified HM shipments. Table 1 presents information on each restriction and designation code. Tables 2, 3 and 4 presents information on the revisions to the route registry.
| Restrictions | Designations |
| --- | --- |
| 0—ALL Hazardous Materials | A—ALL NRHM Hazardous Materials |
| 1—Class 1—Explosives | B—Class 1—Explosives |
| 2—Class 2—Gas | I—Poisonous Inhalation Hazard (PIH) |
| 3—Class 3—Flammable | P—*Preferred Route* Class 7—Radioactive |
| 4—Class 4—Flammable Solid/Combustible | |
| 5—Class 5—Organic | |
| 6—Class 6—Poison | |
| 7—Class 7—Radioactive | |
| 8—Class 8—Corrosives | |
| 9—Class 9—Dangerous (Other) | |
| i—Poisonous Inhalation Hazard (PIH) | |
**Revisions to the National Hazardous Materials Route Registry (March 31, 2023)**
| Designation date | Route order | Route description | City | County | Designation | FMCSA |
| --- | --- | --- | --- | --- | --- | --- |
| 4/2/2024 | C | Add I-295 Oxon Run Creek to I-695 | SE | DC | A | |
| Designation date | Route order | Route description | City | County | Restriction | FMCSA |
| --- | --- | --- | --- | --- | --- | --- |
| 8/29/2024 | D | Ambassador Bridge from [Detroit] Porter St. to Canada [Windsor] | Detroit | Wayne | 1, 6.2, 7 | |
| Designation date | Route order | Route description | City | County | Designation | FMCSA |
| --- | --- | --- | --- | --- | --- | --- |
| 03/20/24 | O | State Route 58 from Interstate Highway 15 to State Route 223 | Barstow | Kern | P | |
| 03/20/24 | P | State Route 223 from State Route 58 to Interstate Highway 5 | Bakersfield | Kern | P | |
End of Revisions to the National Hazardous Materials Route Registry.
Derek Barrs,
Administrator.