The Civil 3D 2011 download is now available on Autodesk’s Subscription Center for subscription customers.
See a download tip after the jump…
DOWNLOAD TIP: When downloading MEP prior to Civil 3D I checked the boxes for each product I wanted to download (32 & 64-bit versions) and clicked “Download Selected Files”. With that method it didn’t seem to kick-off the download properly and just sat at calculating download time. To resolve, I went back and clicked “Download Manager” for each product and it seemed to work fine. Give it a shot if you have troubles.