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49 CFR 390.21(b)(1)

USDOT Marking Size & Placement — FMCSA Rules

Regulation 49 CFR 390.21(b)(1) · Canada

§The Law

49 CFR 390.21(b)(1)Regulation 49 CFR 390.21(b)(1)

USDOT numbers must be displayed in letters at least 2 inches high, in a contrasting colour, on both sides of the power unit in a location where they can be read.

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Plain English

FMCSA requires 2-inch minimum USDOT letters on both cab sides. The cab door is the standard location — visible to DOT officers at roadside stops.

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Specific Requirements

2" minimum height

Cab door or forward cab panel

Both driver and passenger sides

Legible from 50 feet per FMCSA guidance

See Also — Related Regulations

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Regulation Quick Facts

Regulation
49 CFR 390.21(b)(1)
Jurisdiction
🇨🇦 Canada
Category
Cross-Border Compliance
View Official Government Source
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