Map doesn't do the distances justice. You need to explore Texas just once to find out the state is fucking massive. Round Rock to Oak Hill is a hour plus. I am assuming you took the upper 35 through Austin. Don't know much about the toll roads have not been Bach for years and avoided them all together when we were there. If you head east on past Round Rock to Lake Travis there are some good roads out around the lake. The scenery is good out that way too. Feeling nostalgic now. May have to plan a trip to Texas.