Watch out!

Thunk-a thunk-a thunk-a BANG!

That's the sound of Michigan roads this time of year. And it's going to get worse before it gets better.

Michigan's not a bad place to live, if you're looking for someplace with 4 seasons. Unfortunately, one of those 4 is Pothole Season. (The other 3 are hockey, fishfly, and contruction.) Our weather this winter has fluctuated from record lows to record highs. Nice to break up the monotony; not so good for the roads.

Here's what happens. Water gets into small fractures in the concrete. When the temperature drops below freezing, the water that's in the roadway freezes. Which makes it expand, creating fractures. The next time it thaws, water gets into the new fractures, and the cycle starts again. Newly poured roads are less likely to have problems, since they have fewer cracks in them at the beginning of the season. Really badly damaged roads seem to exhibit fewer potholes, too, if only because so much of the road surface has worn or broken off that deep holes can't develop.

But there are a lot of roads in the area that had just enough damage when winter rolled around to be really treacherous now. It's the time of year when the shoulders of the freeways are littered with wheel covers that have been jarred off, and drivers changing tires flattened by hitting a hole hard enough to damage tires or wheels. The time of year that driving routes must not only allow for traffic, but for road conditions. Don't even think about going down some stretches of some streets, unless there's no traffic, so you can dodge the holes.

It's a good time of year to stay home. At least until construction season starts.