It’s called “slugging”. No, I’m not talking about baseball. Slugging is casual carpooling with strangers. It might sound weird and scary but it works for commuters in Washington, D.C. and some other major cities.
Check out this interesting story about slugging: http://www.miller-mccune.com/culture-society/slugging-the-peoples-transit-28068/
Maybe if Austin ever gets HOV lanes, we could see slugging here. Would you do it?