---
kind: "section"
citation: "49 U.S.C. § 31504"
title: "49"
title_heading: "Transportation"
number: "31504"
heading: "Identification of motor vehicles"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/49/31504"
units:
  - "Subtitle VI — Motor Vehicle and Driver Programs"
  - "Part B — Commercial"
  - "Chapter 315 — Motor Carrier Safety"
---

# §31504. Identification of motor vehicles

- (a) **General Authority.—** The Secretary of Transportation may—
  - (1) issue and require the display of an identification plate on a [motor vehicle](/usc/49/30102.md?p=a-7) used in transportation provided by a motor private carrier and a motor carrier of [migrant workers](/usc/49/31501.md?p=1) subject to [section 31502(c) of this title](/usc/49/31502.md?p=c), except a motor contract carrier; and
  - (2) require each of those motor private carriers and motor carriers of [migrant workers](/usc/49/31501.md?p=1) to pay the reasonable cost of the plate.
- (b) **Limitation.—** A motor private carrier or a motor carrier of [migrant workers](/usc/49/31501.md?p=1) may use an identification plate only as authorized by the Secretary.

## Source credit

(Pub. L. 97–449, Jan. 12, 1983, 96 Stat. 2439, § 3104; renumbered § 31504 and amended Pub. L. 103–272, § 1(c), (e), July 5, 1994, 108 Stat. 745, 1030.)

## Notes

| Historical and Revision Notes |  |  |
| --- | --- | --- |
| Revised<br>Section | Source (U.S. Code) | Source (Statutes at Large) |
| 3104(a) | 49:304(a)(3) (last sentence) (related to “Sec. 324”). | Feb. 4, 1887, ch. 104, 24 Stat. 379, § 204(a)(3) (last sentence) (related to “Sec. 224”); added Aug. 9, 1935, ch. 498, 49 Stat. 546. |
|  | 49:304(a)(3a) (last sentence) (related to “Sec. 324”). | Feb. 4, 1887, ch. 104, 24 Stat. 379, § 204(a)(3a) (last sentence) (related to “Sec. 224”); added Aug. 3, 1956, ch. 905, § 2, 70 Stat. 958. |
|  | 49:1655(e)(6)(D) (related to “Sec. 324”). | Oct. 15, 1966, Pub. L. 89–670, § 6(e)(6)(D) (related to “Sec. 224”), 80 Stat. 940. |
| 3104(b) | 49:304(a)(3) (last sentence) (related to “Sec. 324”). |  |
|  | 49:304(a)(3a) (last sentence) (related to “Sec. 324”). |  |
|  | 49:l655(e)(6)(D) (related to “Sec. 324”). |  |

The section is included to reflect the text of former 49:324 (related to motor private carriers and motor carriers of migrant workers) which is incorporated in the revised title by cross-reference.

### Editorial Notes

### Amendments

1994—Pub. L. 103–272 renumbered section 3104 of this title as this section and amended it generally, restating it without substantive change.