Superelevation Transition Length for multiple lanes

[pkrajan]

Hi, Civil 3D superelevation calculation wizard allows us to select maximum 2 lanes on each side. Is there a way in C3D to calculate superelevation transition length for more lanes. Also, it seems C3D calculates transition length based on the standard lane width (3.65m), regardless of what lane width we give. Regards, Pravin Kumar Senior Highway Design Engineer Bechtel, UAE

[Jason.Ferrelli]

For the transistion length values, the out-of-box criteria files that Civil 3D provides, there is a simple formula based on AASHTO standards that will calculate the superelevation for a given radius and design speed. If you want, you can create or modify your design criteria file so the superelevation is calculated differently or, you can edit the superelevation after you calculate it (allowing the default values to get you close).

[pkrajan]

Thank you, Jason Though you started with Superelevation transition length, you have explained about superelevation. I don't have any issues with superelevation. Also, you are right we can edit even the calculated transition length values. As you know, superelevation transition length is based on superelevation, number of lanes, width of each lane and maximum relative gradient. Nowadays, most of the highways have minimum 8 lanes (4 lanes on each direction). Does really Civil 3D (with out of box criteria) allow only up to 4 lanes (2 lanes on each direction)? Hard to believe it.... Please consider adding option for more lanes, because many of Civil 3D users blindly use such values. In our case, we have total 8 lanes of 3.75m width (4 x 3.75 = 15 m on each direction). Therefore, the difference between calculated value of Civil 3D and the required value will be significant. Regards, Pravin

[gzaniel]

I am trying to use Superelevation wizard to calculate three lane on the left and tree lane on the right side of an alignment.  Can you tell me the steps I need to take to accomplish this