As the contractors and power companies have gotten experience putting in SCs, the amount of time from breaking ground to done is looking more like 4-6 weeks. In the Northwest, ADK seems to have it down pat. The Detroit lake charger is almost done and they started the work this month.Yes, the Superchargers are coming on-line at a faster and faster rate. With Rapid City, this is two coming on-line this week without being noticed by any of the scouts. If you just look at the confirmed, under-construction sites from Tesla Wiki Superchargers and Supercharger Progress - Tesla Motors Club, you get 11-12 currently under construction sites that we know about. With a rough completion time of 2 months, that supports a new, on-line rate of 6 per month; add to that the ones under the radar. Its getting interesting...:biggrin:
See my suggestion at Tesla Supercharger locations - Discussion - Tesla Motors Club - Enthusiasts & Owners Forum to start tracking install dates. Sometimes plotting the installs vs time and the install rate vs time can provide some insight towards extrapolating the future.
Based on the winter 2013 map, I'd bet there is a bunch of activity in Utah along I 15 that we haven't heard about (not many Teslas out that way), along I 85 from Atlanta north and along I 95 from Port Orange to Rocky Mount. Also, expect chargers in Wyoming, South Dakota and Minnesota. The transcontinental route will be happening in the next 3-4 months. I bet they are saving a Utah SC for last in order to do a symbolic golden spike. It would be really cool to have that SC near the original location but it's not really a good site (not near an interstate highway).