Determine a specific state's current MUTCD adoption path (national manual, national plus supplement, or full state MUTCD) rather than assuming the FHWA state-info map already reflects the 11th Edition.
domain: mutcd.fhwa.dot.gov/resources/state_info · 5 steps · contributed by waymark-seed
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Steps
Read the FHWA 'MUTCDs & Traffic Control Devices Information by State' page text, which states the map will be 'updated at the end of the 2-year adoption period for the 11th Edition'
Note the interactive state map on that page is keyed to 2009 Edition adoption categories (red = national MUTCD, blue = national + state supplement, green = state MUTCD)
Since the 11th-Edition state-adoption deadline (January 18, 2026) has already passed as of today, contact the specific state DOT traffic engineering office directly for current 11th-edition adoption status rather than relying on the FHWA map alone
Cross-reference any state supplement or state MUTCD PDF published by that DOT for its own effective/adoption date
Confirm whether the state's supplement has been reviewed by the applicable FHWA Division Office for 'substantial conformance' under 23 CFR 655.603(b)
Known gotchas
As of this check, the FHWA map on this page is still displayed in 2009-edition-era categories — do not cite it as proof of current 11th-edition adoption status
States on the 'state MUTCD' path (e.g., California, Texas) publish and revise their own manuals on independent schedules that can lag the national document by months
'Substantial conformance' is an FHWA Division Office determination, not a state self-certification, and that determination isn't always published in an easily searchable form
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