Regulatory Road Sign (R2-1)
Speed Limit 55 Sign Meaning & Driving Rules
The Speed Limit 55 sign (MUTCD R2-1) establishes the statutory maximum lawful travel speed of 55 miles per hour under ideal, clear weather and dry pavement conditions.
Required Driver Action & Right-of-Way Protocol
Maintain a steady travel speed at or below 55 mph. Reduce your speed significantly if weather, visibility, or traffic conditions deteriorate.
Detailed Overview & Purpose
Speed Limit signs are regulatory devices carrying the full force of state traffic law. Driving even 1 mph above the posted 55 mph under optimal daylight conditions constitutes an absolute speeding violation.
However, under the universal Basic Speed Law, you may never drive faster than is safe for existing road, weather, visibility, or traffic conditions. If rain, snow, ice, fog, or heavy congestion is present, you must reduce your speed below 55 mph to maintain vehicle control.
Key Standard & Origin: In 1974, the Emergency Highway Energy Conservation Act mandated a national 55 mph speed limit across all US highways to conserve petroleum; states regained speed authority in 1995.
Where You'll Find This Sign
Installed along two-lane rural highways, undivided state corridors, urban expressways, and arterial bypasses.
Common Driver Mistakes to Avoid
Treating 55 mph as a safe speed during heavy downpours, thick fog, or icy road conditions.
How This Sign Appears on the DMV Knowledge & Road Test
Tests the legal relationship between the posted absolute speed limit and the Basic Speed Law.
Legal Penalties and Moving Violations
Speeding citations range from $150 to $500+ depending on mph over the limit, adding 1 to 3 license penalty points.
Sign Variations & Related Types
Night Speed Limit (R2-3)
A sign with a black background and white numbers specifying a lower maximum speed after dark.
Truck Speed Limit (R2-2P)
Sets a lower legal maximum speed for commercial trucks and trailers.
When you encounter the official Speed Limit 55 (R2-1) on a roadway, what is your legal duty?
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