Overthinking it again

One of the segments in the old Road Runner cartoons featured Wile E. Coyote painting a tunnel on the side of a cliff, hoping the Road runner would crash into it. The gag is fine as far as it goes, but my question is this:

There is a paved road leading up to the side of the cliff, which continues on the other side of the cliff. Why would someone build, pave and maintain a road that goes up to a cliff, and then continue on the other side with no way to get through? Are government bureaucrats in the Looney Tunes universe approving make-work projects to make sure they use up all of their budget?

Better yet, why would the Road Runner be going down that road anyway? If Mr. Coyote decided to become a vegetarian, would RR just stop and go back the other direction?