It was explained to me that SS4/SS10 cannot handle reverse vertical curves (no intervening tangent, PVT and PVC are same station). The workaround is to make one of the curves slightly shorter, for example if you have three 600 foot reverse curves, the middle one needs to be 599.999 feet for the program to work. Reverse curves are a basic design option and have been accommodated in RDS, GEOPAK, etc. Hickerson Route Location and Design, which was first published almost 100 years ago, has a sample reverse vertical curve problem. Has this programming error been corrected in ORD?
You can do them, but they don't annotate correctly as of 2020R1 (I think they annotate as PVT and PVC simultaneously). I haven't had a chance to test them in 2020R2. I submitted an Enhancement Request last October (1061770).
Ahh, Hickerson. One of the great books of modern times.
We must be about the same age, Ray... and I agree!
Mark