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Road narrowingUnited States

An introduction to the traffic rules and road signs of United States. Learn about driving, road safety and much more in our illustrated book, with answers to frequently asked questions.

For informational purposes only. Always follow official regulations. Some content and images were created with AI assistance.

Traffic signs
Traffic rules
United States

21. Road narrowing

A road narrowing is a section where the available width of the road or carriageway becomes smaller. The narrowing may occur on both sides, on one side only, or because one or more traffic lanes end.

Drivers should reduce speed, observe approaching and adjacent traffic, maintain sufficient lateral clearance and merge when necessary. Warning signs do not always determine priority, so drivers must follow any priority signs, lane markings and local traffic rules.

Road narrowing
Road-narrows warning sign on SW 229th Avenue. (Hillsboro, Oregon, United States)
Wikimedia.org • M.O. Stevens • CC BY-SA
What does a road-narrowing warning mean in the United States?

In the United States, warning signs such as Road Narrows or Narrow Bridge identify restricted width. In California, apply the state’s safe-speed and lane-changing rules; a warning does not give junction priority.

🔗 dmv.ca.gov • California DMV — navigating roads, lane markings, turning, merging and passing

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

Does a narrowing warning give you priority in the United States?

No. A warning describes the reduced width, rather than allocating priority or setting a numerical speed limit. Follow any separate priority signs, signals and meeting rules, and slow enough to pass safely or wait before entering.

🔗 dmv.ca.gov • California DMV — navigating roads, lane markings, turning, merging and passing

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

What should you do if traffic lanes merge at a narrowing in the United States?

In California, check mirrors and blind spots, signal and merge only when safe. Use the actual lane controls and any traffic-management instructions; a Road Narrows warning does not itself give the ending lane right of way.

🔗 dmv.ca.gov • California DMV — navigating roads, lane markings, turning, merging and passing

🔗 mutcd.fhwa.dot.gov • FHWA MUTCD11th Edition including Revision1 — relevant signs/markings; device standard, not state law

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