Washboard road is a phenomenon that affects dirt and gravel roads from America to Australia and everywhere in between. It’s simple physics: have you ever noticed how wind blowing over a body of water makes ripples? Or how the waves in a lake or ocean make the sand at the bottom into a washboard pattern? Or how windy, snow-covered mountains sometimes appear to have ripples? This is the same principle that causes washboard road. Vehicles moving over the gravel or dirt, especially at high speeds, move the material and eventually cause a series of uniform ripples to form. Small washboard bumps have even been known to form on steel railroad tracks after prolonged use.
How can you prevent washboard?
You can prevent washboard from forming on your gravel or dirt road by following one simple rule: don’t drive too fast! Studies have shown that any traffic going over about 3 mph is going to cause washboard eventually, but if you stay under 20 mph, it will form very slowly. So the key to prevent washboard (for the most part) is to stay under 20 mph.
When washboard does develop, the easiest and most effective way to get rid of it is to grade your road. Grading will loosen up the gravel or dirt that has become compacted and spread it around evenly. The best quality driveway graders use rigid teeth to dig deeply into the gravel, then use a rear leveling blade to distribute it evenly. Check out the DR Power Grader as an example.