When you think about self-driving vehicles, you probably think cars. But what about semi trucks?

SAN ANTONIO, Texas (WOAI) - Self-driving semi trucks are among the autonomous vehicles now being tested at Southwest Research Institute in San Antonio, Texas.

On the outside their test truck looks like a typical big rig, but once you're inside it turns into something that most might compare to a "Transformers" movie with the push of a button.

"You actually get used to it surprisingly quickly," test driver Stephan Lemmer told WOAI, our NBC station in San Antonio.

Southwest Research Institute, along with several other research organizations, are helping the U.S. Department of Transportation create guidelines for developing automated vehicle technologies.

The end goal is to make our streets safer.

"I think 90 percent of all accidents are caused by human error, and so robots don't get sleepy or tired or drunk or anything like that," notes SwRI Manager of Research Chris Mentzer.

Selected from an applicant pool of more than 60, the Texas AV Proving Ground Partnership joins 10 groups nationwide that will be instrumental in helping the USDOT provide critical insights using big data to further develop guidelines for developing automated vehicle technologies.

The Fredericksburg Road/Medical Drive corridor has been identified as a “real-world environment where a variety of scenarios may be explored.”