A variety of posts are available for mounting traffic signs. Some of the posts include Square Steel, Round Steel, U-Channel Steel and Wooden Posts. Most Department of Transportation (DOT) agencies require some type of breakaway system. Steel posts involve a base post driven or mounted into the ground and then the top post is attached via a breakaway hardware system to the post base. Some states require simple ground mounting (directly buried into the ground) while other states require pre-fabricated sleeves concreted into the ground in which the post is mounted. All posts require two holes to be drilled into the post near the base at strategically located positions to make it a breakaway system, strategically located, to create a breaking point should it be struck by a vehicle.
What type of post should you use?
One of the most cost-effective posts, longevity, widely used.
U-channel posts are typically available with green (average life expectancy of 68 years) or galvanized coatings (exceed 10 years in life expectancy), however, the galvanized are more expensive. There are several different weights (pounds per foot) of sign posts. Our experience with the U-channel posts are that during windy conditions they tend to rock back and forth much more than other types of posts. This wind and rocking tend to cut a path or a groove into the ground due to the shape of the post. This can cause the base to come loose and an entire post and signed to lean and in some circumstances even break.
Square Metal Posts
Increasing in popularity, sturdier than U-channel, better aesthetics and more options.
Square posts come with galvanized coating and are typically pre-punched on all 4 sides with holes spaced every inch. They are also available without the pre-punches being knocked out. The 2 inch square post is the most popular; however they are also available in 1 3/4 inch and 2 ½ inch sizes. Our experience, the square post is much sturdier than the U channel; provides better aesthetics; provides more options than the U-channel; and allows you to mount signs on all four sides of the post unlike the U channel. And, the square post does not rock and cut into the ground like the U-channel post.
Accepted and used in various states for mounting traffic signs.
Wooden posts are made out of treated lumber. They come in a variety of sizes with some of the most common being 4″ x 4″, 4″ x 6″, and 6″ x 6″ just to name a few. Some states require simple ground mounting (directly buried into the ground) while other states require pre-fabricated sleeves concreted into the ground in which the post is mounted. All posts require two holes to be drilled into the post near the base at strategically located positions to make it a breakaway system, strategically located, to create a breaking point should it be struck by a vehicle.
Round posts are another option for mounting signs. However, most state Department of Transportation (DOTs) do not use the round posts. Some local government agencies use the round posts for their aesthetic value. Many new developments use them for their street name signs. The standard size is 2 3/8” O.D. and they are galvanized.
There are several ways of mounting the posts: direct barrel into the ground; the Oz base which is a 3 foot spear spackled base driven into the ground and the post inserted into the base and a collar is tightened into the base and around it. And the final way is a surface mounted base that is bolted to a surface such as concrete, the post is inserted into the base and bolts are tightened to hold the post. The round post is a nice look however, it is more expensive as the signs must be attached with round post brackets coifing more than the standard bolt & nut.