You guys are right, the 6 min sol's do have AM problems, I just don't agree with the advice to tell someone who is taking the Structural depth to buy the Transpo depth 6 minute solutions book. I took the Transpo Depth and bought the Transpo depth 6 minute solutions book (the problems took me way more than 6 minutes by the way) but I did not even consider buying the other depth module 6 min books (each $50+). The type of Transpo problems on the AM exam (please see the NCEES syllabus) can easily be found covered in CERM (hor curves, vert curves, sight distance, super el, etc.). Heck, most of the needed formulas for these topics can be found for free from various agencies. His question asked which reference he should use for the Transpo AM questions. In my opinion, the answer to that is CERM, not the Transpo 6 min sol's.