The HY-8 is a computerized implementation of FHWA culvert hydraulic approaches and protocols. The FHWA publication "Hydraulic Design Series 5: Hydraulic Design of Highway Culverts" (HDS-5) [publication FHWA-NHI-01-020, May 2005 revision] documents the technical methods applied in the HY-8 program and should be considered the primary technical reference for the software. In 2005, the FHWA contracted with the Brigham Young University to develop a 32-bit (and 64-bit) Windows compatible version of HY-8. This version provided graphical user interface (GUI) for the same hydraulic calculations performed in DOS versions of HY-8. FHWA intended to plan and fund this development effort using a series of planned phases. The first phase resulted in an initial release (version 7.0) that performed basic culvert hydraulics. The second phase (version 7.1) incorporated energy dissipater module; performed hydraulic analyses of embedded culverts; allowed use of modified outlet loss coefficients; incorporates dynamic culvert shape database with new materials; and implemented various improvements, technical updates, and bug corrections.

The objective of this research effort is to continue the phased development of HY-8. The effort would be funded by FHWA and other State DOT contributors (PFP members). The anticipated scope of work consists of continued development efforts on the HY-8 software (beginning with phase three of the on-going development effort). The project will consist of the tasks described below. Where possible, the tasks may be developed concurrently. Some tasks will require technical review and approval by PFP members before any programming efforts. Task 1 - Project Meetings Task 2 - Enhance Source Code Efficiencies Task 3 - Hydrograph Routing Task 4 - Hydraulic Jump Code Implementation Task 5 - Broken Back Culvert Code Implementation Task 6 - Allow Modification of the Individual Analysis Discharge Values Task 7 - Horizontal Culvert Barrels Task 8 - Adversely Sloped Barrels Task 9 - Flared End Sections Task 10 - Concrete Open-bottom Arches Task 11 - South Dakota's Prefabricated Reinforced Concrete Box Culverts

Suggested Contribution: $10,000/year. The Federal Highway Administration will serve as the coordinator for this pooled-fund project. State DOT's will be solicited for their interest and participation in this study. FHWA will issue a task order contract under the NHI IDIQ contract conduct the study. Periodic reviews will be arranged to keep participating states and agencies up-to-date on current developments. These reviews may include meetings in Washington D. C. during the annual TRB Session, e-mail submittals and conference calls. Technical Contact: Mr. Joe Krolak Senior Hydraulics Engineer Office of Bridge Technology, E75-339 Federal Highway Administration 1200 New Jersey Avenue, S.E. Washington DC 20590 202/366/4611 joe.krolak@dot.gov