That's called 'washboard'. I believe it is caused by the running water when it rains. It's the same effect you see on the beach sometimes.njvike said:Speaking of road in the pines, what causes the roads to be so uneven and really bumpy? We have dirven down some roads that will make your fillings come out. Is this the cause of tires from mountain bikes and ATVs?
I see that they normally grade the roads very flat.