In 6 years of riding and training in this area I have never encountered a serious problem with any vehicles. The worst that has happened is that I have had a horn honked at me a few times. Most of the other motorists are very respectful and give a wide space when passing. Since there are no bicycle paths you will be forced to ride on the roads. But make an attempt to stay off of Shelbyville and Taylorsville Roads.
Traffic is very heavy, and fast, and there is no shoulder to ride on.
I have a couple of short loops of roads that I like to do my race training on. This is one of the favorite rides for me. Starting at Floyds Fork Park off of Taylorsville Road take a right on to Old Taylorsville Road. Follow this road and you can see the Fork through the tree s. The first road you come to take a left onto English Station Road.