Maintaining a gravel driveway can be a year-round task. When it's wet in the spring and summer or frozen in the winter, the soil and stone are constantly moved and potholes or ruts can be a bother. Regularly adding more gravel keeps the mud and water at bay, but then leads to issue of levelling the surface for easier driving. Making a levelling tool can save money and produce professional results.
The easiest homemade gravel leveller is nothing more than a sturdy length of wide lumber (at least 25 cm (10 inches)) attached with chains to an automobile or lawn tractor. Although boards come in various lengths, avoid using lumber longer than 240 cm (8 feet). Longer boards will bend and maybe even break under the stress of being pulled and weighted against the gravel. If the driveway is very wide, make several passes over the surface.
The one complication is adding some weight so the leveller will dig in and level the gravel and not just bounce along on the top of the driveway. A good source for ideal heavy weights are pawn shops or other used sporting equipment sources; get some 22.5 kg (50 pound) barbell weights. Buy several to do the job, but avoid one very heavy weight that's difficult to move.
At regular intervals along the length of the board, drill holes and install 25 cm (10 inch) carriage bolts with nuts securing the bolt on both sides. Depending on the strength of the board, two boards together may provide greater strength for scraping and levelling heavy gravel. Four sets of two 22.5 kg (50 pound) weights will add 180 kg (400 pounds) to the board. This should be adequate to move the stone and level the surface.
Stack the weights on the bolts and attach chains to each end of the board. Attach the chains to the vehicle tow hitch. The steepness of the driveway may determine whether a large washer and another bolt are needed to secure the weights. Don't worry if the weights are loose and the bolt is smaller than the hole through the weights. The purpose is to add mass to the leveller and not to be pleasing to the eye.
Avoid going too fast when levelling the gravel. A slow, even pace will allow the leveller to pull, push and move the gravel. Too much speed, and even with the added weight, the leveller may just bounce over the surface and not do any work. Take the time to make several passes over the surface. Don't be upset if it's not level after just one pass.