Why hasn't there been another Road Rules season on MTV?

Question

They have produced plenty of Real Worlds, and tons of those "Challenges" but why no more Road Rules seasons? Is it because the "Challenges" are taking its place?

Answer 1

Road Rules is going through a massive overhaul according to this blog (below for link):

"The fate of Road Rules is apparently being left up to MTV, who will soon decide to pick up the new season which was pitched to MTV by M Theory Productions, which we reported on earlier. The retooled version of the series will apparently have more audience interaction. The show was unofficially left "on hiatus" after the airing of its thirteenth season."