Skip to main content
University
of
Nebraska–Lincoln
Log In
Search
Search
Submit
Close
Midwest Roadside Safety Facility
Menu
Search
Log In
Home
Who We Are
History
Faculty/Staff
Employment
Contact Us
Services
Testing
Finite Element Analysis
Design/Consulting
Pooled Fund
About
Member States
Active Projects
Members Only
Tech Transfer
Newsletters and Featured Research
Research Hub
AFB20 (user/password required)
Pooled Fund Q&A
Q&A Home
Ask a Question
Search Questions
Q&A Reports
Login
Q&A Home
Ask Us A Question
Search Answered Questions
Q&A Reports
Login
Nebraska
MwRSF
Q&A Home
Seach Q&A
View Q&A
View Q&A
Ballasting Work Zone Devices
Question
State
MO
Description Text
MoDOT encounters a wide variety of ballasts across a number of work zone devices and isn’t always sure that they’re acceptable. The Roadside Design Guide (RDG) does not have a great deal to say on the issue of ballast for work zone devices. It speaks only of channelizing devices and says, “The ballast should not present an obstruction if the cone is struck” and then goes on to list double-stacking, heavier devices, sandbags or recycled tire rings as acceptable solutions. The only other mention is that rocks and chunks of concrete are not acceptable.
Questions:
• Are there any general rules of thumb (material? Height? Weight?, etc.) for ballast that would allow an agency to conduct a visual inspection and deem an installation appropriate?
• Is the RDG guidance enough?
• Do the rules apply to other devices such as moveable barricades and X-base portable sign supports?
• Are the ballasts shown in the attached .pdf acceptable?
System Performance Evaluation
System Types
Sign Supports and Work-Zone Traffic Control Devices
Applications
System Features
Date
January 30, 2013
Previous Views (132) Favorites (0)
Attachment
Ballast.pdf
Response
Response
(active)
We are not aware of any formal guidance on ballasts for channelizing devices, moveable barricades, nor X-stand portable sign supports. Based on the guidance in the AASHTO
Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals
, the maximum stub height is 4 inches. Therefore, the height to the top of the ballast should not be more than 4 inches above the roadway surface. In addition, the ballast should not be elevated nor should it interfere with the breakaway features of the device. In addition to the RDG guidance, ballasting should be deployed in a similar manner to either the tested configuration or the manufacturer’s recommendation for ballasting
Common ballasts we have seen are sandbags and recycled rings as you have shown in the attached pictures. I would have concerns with placing recycled rings around the center of an X-stand as shown on the second page of the attached photos. This ballast placement could potentially affect the performance of the breakaway mechanism when impacted.
These general rules could be applied to all work zone devices, such as channelizing devices, moveable barricades, and X-stand portable sign supports.
Date
February 28, 2013
Previous Views (132) Favorites (0)
Some parts of this site work best with JavaScript enabled.