It seems logical to start the AP with the Civil AP. The requirements are:

1. Prepare one original scale drawing of a model railroad track plan, identifying overall size, scale, track elevations, curve radii, and turnout sizes.
2. Construct and demonstrate, the satisfactory operation of a completed section of the model railroad and track work described in #1. Containing at least 25 linear feet in Z, N, or TT scale, or 50 linear feet in HO or S scale, or seventy five linear feet in O scale, or 100 linear feet in G or #1 scale, or other scales in proportional relationship to HO scale, with appropriate ballast, drainage facilities, and roadbed profile, which may contain spurs, yards, etc.
3. Construct for Merit Judging, scratch built scale models of three different track features, and demonstrate their satisfactory operation.