Iowa Department of Transportation - LRFD
Florida Department of Transportation Software. Mostly MathCad for precast girder design, liveloader, column design, and ect.
A few Excel design spreadsheets, and MathCAD design examples (pdf)
NYDOT Software - MathCad documents for design of Abutments, Wingwalls, and Elastomeric Bearing Pads
WSDOT Software - Open Source software. Includes precast gider design, pile foundation analysis, splice girder design, and live loader
PTC MathCAD Documents