U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
The MUTCD provides suggestions for methods to be used:
For a typical rural road with no shoulder, the sign should be placed on the right side of the roadway, 12 feet laterally from the edge of the traveled way. In terms of vertical height, the bottom of the sign should be installed 5 feet above the ground elevation at the edge of pavement.
In a situation where it is desirable to enhance a sign's conspicuity, any of the following methods may be used:
Stop Sign (R1-1)
Sign Size
The minimum size for a STOP sign shall be 30" x 30" for a typical rural, two-lane facility.
Stop Bars
Design
Stop bars shall be a solid white line.
Stop bars should be 12-24" wide.
Placement
The stop line should be placed at the desired stopping or yielding point, but should not be placed more than 30 feet or less than 4 feet from the nearest edge of the intersecting traveled way.
Pavement Markings
Design
Markings should be visible at night by use of retroreflectivity or ambient illumination (Section 3A.03).
The MUTCD specifies allowable colors for pavement markings and the function of each color. (Section 3A.05).
Placement
To avoid confusion to the road user, pavement markings should be placed according to the MUTCD, and pavement markings which are no longer applicable should be removed (Section 3A.02)
All Signs
When to use
The use of warning signs shall be based on an engineering study or on engineering judgment.
Placement
Warning signs should be installed in advanced of the intersection in accordance with Table 2C-4, which provides placement distances based on speed.
Stop Ahead (W3-1)
Sign Size
30" x 30" minimum
These signs shall be installed on an approach to a STOP sign that is not visible for a sufficient distance to permit the road user to respond to the device.
To be used only on the "side road" that must come to a stop.
Intersection Ahead (W2-1, W2-2, W2-3, W2-4)
Sign Size
30" x 30" minimum
The Intersection Warning sign should illustrate and depict the general configuration of the intersecting roadway, such as cross road, side road, T-intersection, or Y-intersection.
Advisory Speed Plaque (W13-1P)
Sign Size
18" x 18"
Roadside Placement
The sign height changes when a speed plaque is added. See Figure 2A-2, Page 38, for details.
Two-Direction Large Arrow (W1-7)
Sign Size
48" x 24"
The two-direction large arrow shall be installed on the far side of a T-Intersection in line with, and at approximately a right angle to, traffic approaching from the stem of the T-intersection.
