>>>>"Although I'm sure Jean Claude is not really standing there...."<<<<


Nope, he was really there, although there's a safety line to catch him if he fell. (That was probably painted out using CGI.) And there's a ledge for each foot to rest on. The rest is a real stunt.

http://blogs.wsj.com/speakeasy/2013/11/15/how-volvo-created-the-jean-claude-van-damme-video/

“The stunt is real and is performed in just one take,” said Anders Vilhelmsson, public relations manager for the Volvo Trucks brand. “It’s a daring stunt but we had full control. There was never any real danger involved.”

Van Damme, 53, was hooked to safety lines that aren’t visible in the film, and each foot is on a small platform that was built on the trucks’ side mirrors."