How our world would look without people

The other day while I was driving along U.S. 231 and started up the hill that bypasses downtown, I was struck by one of those out-of-left-field thoughts that often invade my brain for no apparent reason. Something about that wide, smooth stretch of blacktop gave birth to one of my “what if” moments.

I wondered what the highway would look like in a few years if all (or at least most) of us disappeared and there was basically nothing left but the plants and animals. How long would it take for weeds and trees to force cracks and fissures in the asphalt? How many years would elapse before forest and meadow reclaimed the hillside all the way to the river?