Warning Signs
| Sign |
Symbol |
Criteria |
| Turn (W1-1) |
 |
Advisory speed of 30 mph or less |
| Curve (W1-2) |
 |
Advisory speed greater than 30 mph |
| Reverse Turn (W1-3) |
 |
Advisory speed of 30 mph or less and two turns in opposite directions that are seperate by tangent distance of 600 feet or less |
| Reverse Curve (W1-4) |
 |
Advisory speed of greater than 30 mph and two curves in opposite directions that are seperated by tangent distance of 600 feet or less |
Signs are another effective driver-aid treatment. Examples of warning sign treatments for horizontal alignment changes include Turn, Curve, Reverse Turn, and Reverse Curve signs. These signs are helpful but are commonly misused. Use the criteria in the MUTCD as the basis for deciding what type of sign to install.
An advisory speed plaque installed beneath a warning sign provides additional warning to the motorist. Use an advisory speed plaque to advise motorists of the safest speed a vehicle should be driven through a turn or curve. Turn and Curve signs can display advisory speeds in lieu of advisory speed plaques. This type of sign can supplement a turn or curve sign assembly with an advisory speed placard, and is located at the start of the curve.
The One-Direction Large Arrow sign (W1-6) shall be used for short curves and sharp changes in roadway alignment. The sign shall be 24-inches high by 48-inches long.
Consider using chevron alignment signs where delineators do not provide adequate safety. Install signs so that two signs are always in the driver's view at one time, until the change in alignment eliminates the need for the signs.
