June 28, 2000
Refer to: HIBT
David H. Pope, P.E.
Chairman, Highway Subcommittee on Bridges and Structures
Wyoming Department of Transportation
5300 Bishop Boulevard
Cheyenne, WY 82009-3340
Dear Mr. Pope:
Thank you for the letter of June 20, 2000. We appreciate receiving the advice and recommendation of the AASHTO Highway Subcommittee on Bridges and Structures and its member State bridge engineers on the time frame goals for the use of Load and Resistance Factor Design (LRFD) for the design of bridges. We concur in recommended time frames and would be pleased to work in partnership with the States to attain the listed four goals which, to repeat, are:
All new bridges on which States initiate preliminary engineering after October 1, 2007, shall be designed by the LRFD Specifications.
All new culverts, retaining walls, and other standard structures on which States initiate preliminary engineering after October 1, 2010, shall be designed by LRFD Specifications, with the assumption that the specifications and software for these structures are "mature" at this time.
States unable to meet these dates will provide justification and a schedule for completing the transition to LRFD.
For modifications to existing structures, States would have the option of using LRFD Specifications or the specifications which were used for the original design.
A copy of this letter and yours are being provided to the State bridge engineers and our FHWA field offices so that they are aware of FHWA's decision on this matter.
/s/ original signed by
David H. Densmore
Director of Bridge Technology