TrinityHighway.com
8
December 2021
Site Preparation
The CAT® is a tangent, double-sided, re-directive/gating and energy absorbing attenuator/end terminal available for
use with various longitudinal highway barriers, in either unidirectional or bidirectional traffic applications.
It may be specified for use by the state/specifying agency in conjunction with strong post W-beam guardrail systems on
the roadside or median of a roadway. The decision to specify the CAT® for a particular project is the responsibility of
the state/specifying agency design engineer who must ensure that the most appropriate attenuator/end terminal has
been selected for the specific site conditions.
The CAT® is designed to be attached to strong post W-beam guardrail systems that have been accepted under NCHRP
Report 350 crash test criteria that use either no offset blocks, 8” [203 mm] offset blocks or 12” [305 mm] offset blocks.
Important: The CAT® must not be attached directly to a weak post W-beam guardrail
system without an approved weak-post-to-strong-post transition plus a minimum of
12’-6” [3.81 m] strong post W-beam guardrail with 6’-3” [1.91 m] post spacing. The 12’-
6” [3.81 m] strong post W-beam guardrail must be placed between the CAT® Tail and
the weak-post- to-strong-post transition.
Important: The CAT® must not be attached directly to Thrie Beam, Thrie Beam
Transition, or to a post which is stronger/stiffer than a standard W-beam W6x8.5#
[W150x13] or W6x9# [W150x13.5] guardrail post. A minimum of 6’-3” [1.91 m] strong
post single ply W-beam guardrail must be placed between the CAT® Tail and the Thrie
Beam transition (or stronger/stiffer post).
Important: When used with rigid barriers, (i.e. concrete barrier, wall or bridge pier) a
semi to rigid barrier transition will be required (see state/specifying agency standards)
as well as an appropriate CAT® Tail.
Important:
Ensure this CAT® Tail is not used in a median application where the opposing
traffic can impact the blunt end of the CAT® Tail Guardrail, if it is inside the Clear Zone as
defined by Roadside Design Guide (latest edition).
Important: Ensure that the CAT® application conforms to the AASHTO Roadside
Design Guide, current edition.
Important: Trinity Highway does not direct grading. Proper site grading must be
accomplished before assembly of the CAT® in accordance with local guidelines OR the
AASHTO Roadside Design Guide (see Appendix A and B), whichever is more
stringent. Failure to follow this warning could result in serious injury or death in the
event of a vehicle impact with the system.
Important: The Beginning Length of Need (“BLON”) for the CAT® was established
during NCHRP Report 350 Test 3-35 at Post #4, which is 18’-9” [5.71 m] from the center
of Post #1.
