Chapter 1610 (pdf) of the WSDOT Design Manual provides guidance for the different barriers, terminals and transitions that WSDOT uses.
Cable Barrier In-Action
Traffic Barrier: Information and Reports
Length of Need Calculations
An Excel spreadsheet may be downloaded and used to calculate barrier length of need. (xls, 20 kb)
The buried terminal is the preferred terminal because it eliminates the exposed end of the guardrail. The guardrail is anchored in a backslope that is 1V:3H or steeper and at least 4 feet in height.
Buried Terminal Type 2 is used when the foreslope is as steep as 1V:4H. A more abrupt flare is acceptable after the rail passed the bottom of the ditch. The height of the guardrail is maintained relative to the roadway and a rubrail is used along the exposed portion of the posts.
Standard Plan C-22.14 and Standard Plan C-22.16
The Standard Plans identify proprietary nonflared terminal designs. The Standard Plans do not show all of the details needed to construct these terminals. The Standard Plans supplement the manufacturers drawings which can be downloaded below.
For use with 31 inch systems:
The SoftStop is only supplied with steel posts, but can be used with wood post or steel post guardrail runs.
For use with 27 inch systems:
Wood Post Systems
A flared terminal can be used where a buried terminal cannot be installed. These terminals are flared away from the traveled way which creates an offset from the tangent guardrail.
The Standard Plans identify acceptable proprietary flared terminal designs. The Standard Plans do not show all of the details needed to construct these terminals. These Standard Plans supplement the manufacturers drawings which can be downloaded below.
Flared Energy Absorbing Terminal (FLEAT 350) Manufacturer's Drawings
Flared Energy Absorbing Terminal (FLEAT 350) Views:
SRT-350 Manufacturer's Drawings
- SRT 350 (8 Post Design) (pdf, 136 kb)
- The WSDOT has discontinued the use of the SRT 75. For low speed installations, the FLEAT-TL2 can be used.
Manufacturer's plans of older SRT designs
Slotted Rail Terminal Manufacturer drawings:
Roadside Safety Contact
Jeff Petterson, PE
Roadside Safety Engineer