Speed Limit Signs

A speed limit sign tells drivers the maximum legal speed for a stretch of road, and it only works if it's the right sign, the right size, and readable at highway distance. Dornbos Sign & Safety manufactures MUTCD-compliant speed limit signs for municipalities, DOT contractors, campuses, business parks, and private communities.

See the standard R2-1 to advisory speed plaques, reduced-speed warnings, and solar-powered flashing LED units. Every sign is made in the USA on rust-free aluminum with engineer-grade, high-intensity, or diamond-grade reflective sheeting, and orders ship nationwide in 2–10 business days.

What Size Speed Limit Sign Do I Need?

Sign size is set by roadway type, not preference. The MUTCD lists minimum sizes for the R2-1 speed limit sign and allows agencies to go larger in 6-inch increments - never smaller.

Common sizes include:

• 18" x 24" - single-lane conventional roads, low-speed private drives
• 24" x 30" - standard conventional roads (the most-ordered size)
• 30" x 36" - multi-lane conventional roads and expressways
• 36" x 48" - freeways
• 48" x 60" - oversized, for high-speed or high-volume corridors

Placement matters as much as size. Post the sign at or just past the point where the new limit begins, repeat it beyond major intersections, and mount it 5 feet high in rural areas or 7 feet high where there are curbs and sidewalks. Not sure which size applies to your road? Give us a call, and we're happy to go over any details with you before you order.

Advisory vs. Reduced Speed Sign: Which Do You Need?

The sign types below get mixed up at checkout, and ordering the wrong one can make the sign unenforceable or non-compliant.

• Speed limit signs (R2-1) are regulatory - white background, black legend. The posted number is the enforceable legal limit.
• Advisory speed plaques (W13-1) are warnings, not laws. Yellow background, black legend, often mounted below a curve, ramp, or hazard warning sign. The number is a recommended safe speed determined by an engineering study - typically posted when slowing down 15 mph or more below the legal limit. Police can't write a ticket for exceeding it alone.
• Reduced speed ahead signs (R2-5A, R2-5B, W3-5) are advance notice. They warn drivers that a lower limit is coming so they can slow down before they reach it - the standard treatment when traffic enters a school zone, work zone, or town center from a higher-speed road.

A short answer: if you want the speed to be legally enforceable, you need a white regulatory sign. If you're warning drivers about a curve or a hazard, you need a yellow plaque.

Flashing LED and Solar Speed Limit Signs

When a static sign gets ignored, an LED speed limit sign gets noticed. Our flashing LED R2-1 pairs the standard regulatory legend with high-output LEDs around the border, and solar power means no trenching, no conduit, and no electrical permit - it mounts on an existing post and runs on its own. 

Federal, state, and local agencies use speed signs for school zones, speed transitions, work zones, and locations where crash data or complaints show drivers need them. They cost more than sheet-aluminum signs, and they earn it in locations that need them. If you're trying to decide whether a corridor justifies one, we'll talk it through honestly rather than upsell you.

Compatible Speed and Curve Signs

Speed control rarely comes down to a single sign. Customers ordering speed limit signs commonly add:

• W1-1 and W1-2 curve and turn signs with speeds - left and right, symbol plus advisory speed in one panel
• W17-1 SPEED HUMP - advanced warning for traffic-calming installations
• R12-8 seasonal load and speed restrictions - for frost laws and posted road seasons
• Slow Down / Speed Limit 25 signs - neighborhood and HOA speed messaging
• Custom speed limit signs - your speed, your legend, your logo, produced to the same MUTCD sheeting and dimension standards

Need a full corridor package? Send us the list or the plan sheet, and we'll quote the whole job.