Federal Highway Administration
400 Seventh St., S.W.
October 27, 2006
In Reply Refer To: HSSD/CC-87B
Mr. Barry Stephens, P.E.
Sr. Vice President, Engineering
Energy Absorption Systems, Inc.
3617 Cincinnati Avenue
Rocklin, CA 95678
Dear Mr. Stephens:
In your October 11 letter, you requested acceptance of a modified version of your previously accepted QUEST crash cushion called the QUEST 70/100 system. To support this request, you supplied test reports prepared by E-TECH Testing Services, Inc. that described the new system as well as the full-scale crash tests you conducted.
The QUEST 70/100 system is a re-directive, non-gating, modular crash cushion having a test level 2 (TL-2) nominal effective length of 17.65 ft (5.38m) and a TL-3 nominal effective length of 23.65 ft (7.21m). The QUEST 70/100 is 32 inches (813mm) tall. The nominal backup width ranges from 24 inches (610mm) to 36 inches (915mm). Its main components include a ground anchored back-up assembly, two ground-anchored front anchors, two front rails, two rear rails, a nose, a trigger, a sled, a diaphragm, and panel assemblies. Essentially the QUEST 70/100 is longer than the original QUEST and uses laminated sheet metal “peel straps” rather than the solid energy absorbing straps in the original QUEST. The weight of the sled was also reduced.
Enclosure 1 shows the component parts of both the TL-2 and TL-3 QUEST models.
Testing of the QUEST 70/100 system was conducted on concrete foundations, although the original QUEST system was tested and accepted for asphalt applications. The QUEST 70/100 and the original QUEST system share identical front anchors and backups, with the same type and number of anchors. We agree that the asphalt anchoring system of the original QUEST is suitable for use on the QUEST 70/100 system without re-testing. For some tests, the unit was freestanding and for others it was butted directly up against a simulated rigid hazard. When anchored to concrete, the reported foundation must be at least 8 inches (203mm) thick and 30 of your MP-3 anchors (19mm diameter, B7, all-threaded) are specified with an embedment depth of at least 5.5 inches (140mm). The recommended nominal compressive strength of the concrete must be at least 27.6 MPa. When anchored to asphalt, the foundation must be at least 6 inches (150mm) thick over 6 inch (150mm) thick compacted sub-base and 38 of your MP-3 long-bolts (19mm diameter, B7, all-thread) are specified with an embedment depth of at least 16.5 inches (420mm).
The QUEST 70/100 system is designed to be where bi-directional traffic is present. You submitted drawings depicting transitions to w-beam and thrie-beam guardrail as well as “New Jersey” and vertically faced concrete walls. We have noted that these transitions are virtually identical to those validated in other testing programs previously accepted by the Federal Highway Administration (FHWA). We agree that additional crash testing is not required on the transition components.
Crash testing was successfully conducted for all eight certification tests recommended in the National Cooperative Highway Research Program (NCHRP) Report 350 for redirecting, non-gating crash cushions. These tests were conducted at TL-2 and TL-3 impact speeds. The TL-2 tests included 2-30, 31, 32, 33, 36, 37, 38, and 39. The TL-3 tests included 3-30, 31, 32, 33, 36, 37, 38, and 39. Test 3-32 was also conducted on a 36 inch (915 mm) wide model of QUEST 70/100 system since this test has traditionally been the most demanding on a wider system. Each test set-up and its results are described in the enclosed test summary reports shown in Enclosure 2.
Your QUEST 70/100 system meets the evaluation criteria for the NCHRP Report 350 re-directive, non-gating crash cushion at TL-2 and TL-3 impact conditions and may be used on the National Highway System when such use is acceptable to the contracting authority. It may be configured with back-up widths from 24 inches (610mm) to 36 inches (915mm). The transition designs are acceptable when the QUEST 70/100 is connected to w-beam, thrie-beam, New Jersey or vertically faced concrete barrier. Further, the QUEST 70/100 can be anchored to concrete or asphalt surfaces if these surfaces duplicate the minimum anchoring foundations noted above.
Please note the following standard provisions that apply to the FHWA letters of acceptance:
John R. Baxter, P.E
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