My sister, who teaches at Kirkwood, rode her bike there last week. I said on Facebook that I thought it was around a 20-mile ride, but she said she knows that driving to Kirkwood is a 13-mile journey, and I think she correctly points out that although the bike route, which uses a trail and not the Interstate for most of the journey, is not that much longer.
So, it was probably a 15-mile trip, more or less, that she completed in 1 1/2 hours.
Not bad. My own commute, which I made only once last week, is around 5 miles one way--about a 25 minute ride, so my speed is about the same.
I hope, weather willing, to ride down with her one of these days. If I do, I'll write about it. I did the route last summer when the Iowa College Media Association June meeting was held at Kirkwood Community College, but otherwise don't have much reason to head that far south (Cate, my sister, and I both live in the two neighborhoods that are both on the far northern parts of Cedar Rapids, Kirkwood is on the south edge of town).
At least CR is bike friendly enough that there are reasonable ways to cross it border to border!