I added one a year or so ago. I also attached a cool shot of the mountain from one of the geothermal powerplants. It is kind of a cool perspective. What is with all the low votes on this page?
I climbed Cobb Mtn from Whispering Pines on 12/30/2009. The road near the gate seems to get use from locals, however a little ways up the road becomes covered in pine needles and has many fallen trees across it. Most of the roads on this hike haven't been driven on in years, with the exception of the area near the gate and between the two summits with transmitters at the top. I wouldn't worry too much about avoiding work days--any vehicular traffic at the top would be easily avoided by stepping into the bushes.
Boggs Mountain State Forest has a primitive campground that is free. Only services are an outhouse and a few picnic tables. The access road from 175 is about 1.5 miles north of Whispering Pines.