Hi Paul,
I've not done this ride is a couple of years, but I do remember chip seal and black-top roads.  They do a good job of trying to keep you out of traffic but I do remember some hills--before going by the candy factory.  It's a good ride but it's not flat by any means.  You won't have any issues on the ride, but a trike is another matter.  
 
Good luck and enjoy the candy.
Dianna

I did the 65 mile route back in 2007, don't remember much of it other than the starting line was by a large bridge near downtown, was pretty flat, the 60 mile course was a little nub off the 55 route and the road surface wasn't very good. According to my blog some of the route wasn't well marked but it looks like the route in that area is slightly different now so I wouldn't sweat it
 
They gave out Skittles, M&M's and Marathon bars at one of the rest stops (by the factory which made them) I imagine the 100 mile route is the same
 
Should be a decent ride,  
 
http://blogspot.lifeonabaron.com/2007/09/waco-wild-wild-west-100k.html