How can I roadtrip from Columbus, OH to Dallas, TX without paying for a hotel?

So, I am planning on doing a half ironman in Lubbock, TX and I live in OH. I have friends to stay with in Dallas but no where in between here and there. Is there a way I could get showers and someplace to stay along the way without paying for a hotel? I will barely have money for the gas and tolls! Everything I looked at costs money. Any experienced couch surfers out there?