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DESIGN MEMORANDUM NO. 14-97 TO: Chief District Engineers FROM: John B. Sacksteder, P.E. DATE: December 2,1997 SUBJECT: Crash Cushions Type VI, IX and IX-A
This memo voids Section 61-08.03, CRASH CUSHION TYPE IX AND IX-A, in the Departments current Division of Highway Design Guidance Manual. When crash cushions are to be installed on paved surfaces, Crash Cushion Type VI shall be the preferred choice. This device requires a concrete pad and a bolt down system as detailed in the current Standard Drawings. Crash Cushion Type IX or IX-A shall be the preferred choice on earth surfaces. This device requires posts and soil tubes as detailed in the current Standard Drawings. Both of these devices meet NCHRP-350 crash test criteria and can be considered a gating device. Vehicles impacting at an angle on the nose may break through. Therefore, these systems should be installed with adequate recovery zones. Guardrail Installation At Median Piers (Depressed Median), Standard Drawing RBI-007-06, has been revised. Crash Cushion Type IX attached to a concrete backup with a concrete wall between the piers has replaced the existing guardrail and Guardrail End Treatments Type 4A and 5. The new drawing should be included into the plans as a full size detail sheet until a new Standard Drawing Book has been issued. Full size reproducibles for use in roadway plans are available upon request from the Division of Highway Design, Standard Drawing Section. JBS:WSG:DHM:jq Attachment Crash Cushion Type IX Installation at Median Piers
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