I would really like to automate the majority of the superelevation data. However, the transition lengths calculated by the program using the method outlined in the FDOT training manual does not match hand calculated results. Am I missing something? Where does the program read transition rates from? Please explain how RD is calculating the transition length. The hand calculation methods I am using are as follows: Lane Width x Trans. Rate x Algebraic diff in grades= Transition Length , or Vert. Diff (ft) x Trans. Rate= Transition Length. In this particular case, I am trying to set superelevation for a 15' single lane ramp. Thanks.
MS 08.11.07.469
GPK 08.11.07.536
FDOT 2010.04.00
The superelevation data used by the Roadway Designer Superelevation Wizard for FDOT projects is defined in various tables delivered in the FDOT Workspace, specifically the FDOT2010\GEOPAK\corridor\tables folder. These are organized by max. super rate, .05 or .10, and design speed. Each of these text files contain rate data for each of the specific horizontal curve radii at a given design speed, as per the Plans Preparation Manual Volume 1 Tables in Section 2.9. The transition lengths are also defined for two lane undivided or or 4 lane divided per the PPM. However , they are for a standard lane width of 12 feet. In order to use these tables on FDOT projects set the table wizard dialogs as shown below.
If your facility has a 15' lane , use 1.25 as the Runoff Length Multiplication Factor
If you need further assistance please contact me directly
regards,
Vern Danforth, P.E.
CADD Applications Support
Florida Department of Transportation
Engineering / CADD Systems Office
Phone no: (850)245-1618
Toll Free no: (866)374-3368 Extension 1600
email: mailto:vern.danforth@dot.state.fl.us
web: http://www.dot.state.fl.us/ecso
Vern
Answer Verified By: Vern Danforth