Sign Posts
Sign Post Breakaway Systems
Portable Sign Stands
Surface Mount Bases
Post Mounting Tools
Post Caps
Sign Support Systems
Devices used to display a traffic, parking or property sign are known as the sign support, which consists of the vertical sign post and, if needed, any stiffeners onto which the sign panel is attached. Most posts for roadside post-mounted signs are one of the following types:
- Wood post
- U-channel sign post
- Square sign post
- Round sign post
- I-beam steel post
A sign support can become a deadly hazard when struck by a vehicle that drives onto the roadside; therefore, there is an MUTCD standard that requires all roadside sign supports in the clear zone to be breakaway, yielding, or shielded by a barrier or crash cushion. "Breakaway system" is a term to describe crash tested sign supports that break or bend upon impact. This includes sign supports that, when struck by a vehicle, separate from the base and are knocked ahead of or up and over the errant vehicle. A "yielding" support refers to a support that bends, allowing a vehicle to run over it. Barriers are typically not installed to shield roadside signs, especially on local roads; hence, the design of the post, regardless of the type, must provide the breakaway or yielding feature.
All sign supports on highways within the clear zone must either be of a breakaway type meeting the crashworthiness criteria of NCHRP 350 or be shielded by guardrail, barrier, or an energy absorbing system meeting NCHRP Report 350 or the AASHTO Manual for Assessing Hardware (MASH) criteria.
U-Channel Sign Post
U-channel sign post, hot rolled steel post is another common small sign support. It is considered breakaway since it will bend, break or pull out of the ground when it is hit.
U-Channel Post Breakaway System
A U-channel post weighing 3 pounds-per-foot or less meets breakaway requirements by itself. If a heavier post is used, splices can be used to install at ground level.
Square Sign Post
Square steel post with perforated design, which is used in many municipalities. Square sign posts of this type are also considered breakaway if they are 2¼ inches or less in size.
Square Sign Post Breakaway System
As with the U-channel post, sleeve assemblies can be used for the base or slip couplings can be used near the base. These devices will increase the safety of a sign if it is hit and make it easier to repair. After the sign has been hit, the broken stub of the post can be removed from the base sleeve and a new sign post put back in place.
Post Support: The post should be driven into the ground and not encased in concrete. A broken or damaged post is easier to remove if it is not driven or set into the ground more than 3 or 3.5 feet.
