Here are the useful links:
American Public Works Association (APWA) Indiana Chapter
Association of Indiana Counties (AIC)
Federal Highway Administration (FHWA) - Indiana Division
Indiana Association of Cities and Towns (IACT)
Indiana Association of City Engineers (IACE)
Indiana Association of County Commissioners (IACC)
Indiana Association of County Highway Engineers and Supervisors (IACHES)
Indiana Department of Transportation
Institute of Transportation Engineers - Indiana
Joint Transportation Research Program
School of Civil Engineering
TRIS Online (National Transportation Library)