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Roadside Safety Design

WSDOT publishes roadside safety design, including design for traffic barriers, impact attenuators, and rumble strips. State roadside safety policies are covered in Division 16 of the Design Manual.

Major Topics
Frequently Asked Questions (FAQ's)
Cable Barriers
Beam Guardrail Terminals and Anchors
Impact Attenuators
Rumble Strips
MASH Implementation (pdf 139kb)
The Manual for Assessing Safety Hardware (MASH) updated the rules for crash testing roadside hardware. See what FHWA has to say about MASH implementation.

Design Manual
Chapter 1600, Roadside Safety (pdf 678 kb)
This chapter addresses the area outside of the roadway and is an important component of total highway design. Guidance on roadside safety issues is presented in this chapter.
Chapter 1610, Traffic Barriers (pdf 1.2 mb)
This chapter includes traffic barriers, terminals and transitions that are approved for use by WSDOT.
Chapter 1620, Impact Attenuators (pdf 1.8 mb)
This chapter describes the impact attenuators that are approved for use by WSDOT.

(Old) Type 1 Beam Guardrail Design Information
WSDOT is phasing out the use of Type 1 guardrail. A primary reason for phasing out Type 1 guardrail is that all configurations of the Type 1 guardrail are not MASH- compliant, (pdf 139kb) whereas Type 31 guardrail is MASH compliant.

(Old) Type 1 Beam Guardrail Placement Cases (Removed from Design Manual in 2017) (pdf 140kb)
(Old) Type 1 Beam Guardrail Terminals and Anchors (pdf 111kb)
(Old) Type 1 Beam Guardrail Transitions (docx, 23kb)

 SCI 100

The SCI 100 GM Smartcushion was the first MASH compliant Type 31 impact attenuator on the WSDOT QPL. Read more about impact attenuators.

Odds and Ends
Length need calculation spreadsheet (xls, 20 kb) - use to calculate barrier length of need
Type 20 and Type 21 Guardrail (pdf 83kb)- primarily used in conjunction with Service Level 1 bridges; Contact Bridge and Structures Office