August 28, 2002
Mr. Russell A. Walker
Director, Sales & Marketing
P.O. Box 56
Imperial, PA 15126
Dear Mr. Walker:
Your July 25 letter to Mr. Richard Powers of my staff requested acceptance
of a modified recycled plastic offset block for use with w-beam guardrail.
Whereas the original block , accepted on January 9, 1995 (acceptance letter
B-29), was rectangular with a nominal 6-inch width, your modified block tapers
along each side from a 5-inch width at the post flange to a 4.25-inch width
at the traffic face. All other dimensions, including its 7.5-inch depth and
field-side routing remain unchanged.
The modified block described above, and called the PolyLumber PL5814R, is acceptable
for use with strong-post w-beam guardrail on the National Highway System. Please
note the following standard provisions that apply to FHWA letters of acceptance:
- Any changes that may adversely influence the crashworthiness of the device
will require a new acceptance letter.
- Should the FHWA discover that in-service performance reveals unacceptable
safety problems, or that the device being marketed is significantly different
from the version that was approved, it reserves the right to modify or revoke
- You will be expected to certify to potential users that the product furnished
has essentially the same chemistry, mechanical properties, and geometry as
that submitted for acceptance.
- If proprietary devices are specified for use on Federal-aid projects, except
exempt, non-NHS projects, they: (a) must be supplied through competitive
bidding with equally suitable non-patented items; (b) the highway agency must
certify that they are essential for synchronization with existing highway
facilities or that no equally suitable alternative exists or; (c) they must
be used for research or for a distinctive type of construction on relatively
short sections of road for experimental purposes.
(original signed by Carol H. Jacoby)
Carol H. Jacoby, P.E.
Director, Office of Safety design