FPS 19 is the latest version of the flexible pavement design system developed by the Texas Transportation Institute for TxDOT. This version uses backcalculated elastic moduli of the pavement layer materials in the pavement design process. The MODULUS 5.1 backcalculation procedure generates the input layer moduli. The WESLEA linear elastic computer program, embedded within FPS 19, computes pavement responses. The design equation used is the same as used in FPS 11 and documented in TTI Report 32-11. The main design parameter is the Surface Curvature Index computed at the midpoint of a set of dual tires loaded to 40 Kn (9,000 lbs). FPS 19 is microcomputer-based and compatible with MS-DOS Windows 95 and Windows NT when running under the DOS window. TxDOT is implementing the FPS 19 computer program statewide as part of its new flexible pavement design system.