§ 3.3.0. COMPUTERIZED PAVEMENT DESIGN USERS MANUAL (UN-1)

This document represents a user's manual for the two computer programs, Municipal Flexible Pavement Design (MFPS-1) and Municipal Rigid Pavement Design (MRPS-1), for the design and life-cycle cost analysis of city streets. These programs were adapted for municipal use from existing rural highway versions of the SDHPT Flexible Pavement Design, FPS-11 (see Orellana, Hugh E., "FPS-11 Flexible Pavement System Computer Program Documentation," Research Report 123-15 and Texas Highway Department Pavement Design System, Part 1. Flexible Pavement Designs Manual) and Rigid Pavement Design, RPS-3 (see Carmichael, Robert F. and McCullough, Frank B., "Modification and Implementation of the Rigid Pavement Design System," Research Report No. 123-16). Both programs were developed for use by the City of Austin and because of the nature of their development and certain built-in regional factors, (for example, a temperature constant is built into the program based on the average daily temperature for SDHPT District 14 which includes Travis County) use by any other city in a different environment requires a thorough understanding of the program operation and its inherent assumptions and limitations. Furthermore, it should be recognized that these are the initial versions of these programs for City application and that caution is warranted in preparing the inputs and interpreting the results.

Both programs, Municipal Flexible Pavement Design (MFPS-1) and Municipal Rigid Pavement Design (MRPS-1), are written in FORTRAN IV computer language and run on the City's mainframe IBM computer. The programs have similar input data structures and consider several of the significant factors associated with the design of city streets. Guidelines and specific criteria needed for the selection of appropriate input data for both programs are presented in the body of the manual. The input guides and variable descriptions needed for coding individual problems are presented in subsequent appendices: Appendix B for Municipal Flexible Pavement Design (MFPS-1) and Appendix C for Municipal Rigid Pavement Design (MRPS-1).

Each program will generate numerous pavement design alternatives based on performance requirements, rehabilitation needs, and other user-specified design data. Life-cycle costs are then estimated considering initial construction, maintenance, and rehabilitation costs. User costs associated with traffic delays during rehabilitation are also considered. All future costs are converted to net present value using a specified discount rate. Thus, the life-cycle costs of pavement design alternatives can be used in the process of selecting the pavement section. All input variables are described in the following sections.