3-pound u-channel posts are used with Types D, E and F signs and are considered breakaway. They can be erected as a single, double or triple post system.
Single 3-lb U-channel requirements:
- Sign panels or sign assemblies of less than 12sf
- Sign panels 36 inches wide or less (including 36" diamond shape)
Double 3-lb U-channel requirements:
- Sign assemblies of 24sf or less
- Two posts can be used less than 7' apart
If sign assemblies require more than two u-channel supports, the supports shall be placed a minimum of 4 ft. between posts. No more than two posts shall fall within 7 ft. path, or the sign assembly must be placed behind barrier protection.
Back-to-back U-channel posts are not considered breakaway and must be used behind guardrail.
2-pound u-channel posts are used with milemarkers and are considered breakaway.
Use with square tubing in accordance with manufacture specifications.
NCDOT U-Channel Posts for Type D, E, and F signs (Link)
Applicable Standard Specifications
SECTION 903 GROUND MOUNTED SIGN SUPPORTS
SECTION 904 SIGN ERECTION
Applicable Standards Drawings
904.50 MOUNTING OF TYPE 'D', 'E' AND 'F' SIGNS ON 'U' CHANNEL POSTS