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Impact Attenuator Design

Chapter 1620 of the WSDOT Design Manual provides guidance for the impact attenuators that are used by WSDOT.

For new (permanent) installations, the following systems are approved for use by WSDOT:

For both new (permanent) installations and Work Zone (temporary) installations, the following systems are approved for use by WSDOT:

For Work Zone (Temporary) installations, the following systems are approved for use by WSDOT:

Older systems that that have been installed in the past that are no longer approved by WSDOT for new installations:


The WSDOT Headquarters Design Office maintains a list of low-maintenance impact attenuator devices that’s used by our designers in the preparation of project plans and specifications (for more information see WSDOT Design Manual 1620.03).

For a list of the requirements that need to be met in order to be included in the low-maintenance impact attenuator category see:

Low-Maintenance Impact Attenuators - Acceptance Criteria (pdf, 77kb)