39+ Threads on this forum
Sara,
Frequent threads on this forum deal with solo travelers, usually female. If you use the Search function (red button top of this page) and use "solo" as the keyword you will find at least 39 threads addressing this issue.
There are a number of non-profit organizations that arrange roadtrips -- one that I can suggest is run by <a href = "http://www.houstonculture.org">Mark Lacy</a> in Houston. In addition, most of the adventure travel firms (Sobek being the largest in the world) have roadtrip elements in their packages.
The "Share the Gas" section of this forum has put a number of roadtrippers together. It is as safe as anything else in life. Got to use good judgment and not exceed personal thresholds of safety.
Mark