When I apply the Aashto rule base supperelevation, the error "To avoid overlaping the end, the supperelevation applied has been slid to a lower station. Use edit to reposition". I would be grateful if anyone could explain the cause of the problem.
Thanks
Bunrith
Greetings-
Which program are you using? That will help in obtaining a more specific solution.
It sounds like you don't have enough tangent between two curves, or enough between the end of a curve and the end of the alignment. Since AASHTO mandates the transition length to be used and what percent of the super is on the tangent and what percent is on the curve, it's possible to get two curves' supers overlapping when the tangent available between them is less then two times the transition length. Or near the end of an alignment and have a curve just prior to the end such that the amount of tangent on the end is smaller than the trtansition length. In either case, you need to address the overlap. That can be done by modifying the transition length (typically not preferred), or the percentage of super that can be on the curve (the better of these options).
Hi Jcallicott!
Thank you for your help. I am using MX Road to design a simple 2 lane road. I apply transition length of 45m and emax=6% for every curve. The design speed is 80km/h.
Thank you again for your help.