Stop! Look! And Hasten!

Wile E. uses an Acme pop-up wall, a Burmese tiger trap (which, inexplicably, ends up catching him one), Acme Triple-Strength Fortified Leg Muscle Vitamins (Family Size), a vision of the bird coasting along in dinner form, and a motorcycling attempt… all fail. An entire bridge collapses except for the sawed-out section that the Road Runner is standing on.