Originally Posted by
Takara
These trails mostly link small communities via long-abandoned rail right-of-ways and therefore have next to no traffic of any kind. The ones I've ridden in Wisconsin are quite well maintained -- any touring bike can negotiate them without modification. I couldn't recommend these more strongly, especially for a first tour for folks seeking to stay off roads.
Key word here is mostly.
Many of the state trails connect to the Madison trail system. If you hit Madison, expect traffic even if it's the middle of the day. Also, one of the state trails links Madison with the Milwaukee suburbs. I wouldn't expect low traffic on that one either.
If you are interested in a camping tour, the WI trail system is well connected with WI state parks. If you're not interested in camping, you will need *some* ability to handle a bike in traffic... the trails tend to run through towns so it shouldn't take much road riding (say, less than 5 miles) to find a B&B or motel.
IIRC the WI trail network is now connected with the IL state trail network. I don't know what that one is like, but if it's maintained like the WI network it should be quite nice.