Twelve Year Program (TYP) -  A document managed by Commonwealth Act 120 of 1970 as amended that lists those highway, bridge, aviation, public transit, rail freight and intermodal projects for state transportation improvement funding over a twelve year period. The program is: Reviewed, revised, adjusted and extended every two years; developed and administered by the Department of Transportation in cooperation with county planning agencies, public transit agencies, airports and the MPOs and Local Development Districts (LDDs).