Abstract An Interactive Computer Graphics Parking (ICG-PARK) Program which provides an efficient way to design parking lots is described. Using ICG-PARK program, composite pictures of the system can be generated by computer graphics quickly and accurately. The modification or redesign of such pictures can be done easily through interactive display systems. The area under study is initially drawn with fixed objects. The user can then proceed to any desired subroutine by using the interactive capabilities of the system. The length, direction of row(s) of parking spaces and the dimension of the parking stalls are given by the user each time through the interactive device when a parking stall drawing subroutine is called. Row(s) of parking stalls are drawn on a subpicture. When attached to the cross cursor, it can be moved to the desired location. The approximation of a curve can be drawn by calling the curve drawing subroutine recurrently. The design vehicle minimum turning path curve is provided, and can be used to check the adequacy of the aisle, entrance, and exit layout. The CRT screen can be erased either entirely or partially and redrawn at any time. Finally, a hardcopy of a satisfactory parking lot layout plan can be obtained through the plotter.