 Earth and gravel roads are a very important part of the highway network. These roads are frequently the only connections for rural populations and the means of getting farm products to market. Earth and gravel roads are not as strong as asphalt roads. They must be maintained regularly because bad weather and heavy traffic quickly cause surface deterioration. A road may have a rough surface, but still has a crown or center higher than the edges, which allows water to drain. This type of road will only need to have the surface smoothed. This operation is called smoothing. However, if the road surface is very rough and water does not drain properly because the crown is lost, but sufficient surface material remains on the road, the crown must be restored by moving the surface material from the edges toward the center of the road. This operation is called reshaping. If a gravel road has lost most of the granular material, neither smoothing nor reshaping will restore the road to a good condition. It must be re-graveled to re-establish the wearing course. Refer to the IRF videotape re-graveling for further instructions. Frequent smoothing and reshaping will keep earth and gravel roads in good condition and reduce the need to do other major maintenance work. If these operations must be done during dry weather, spray just enough water on the road to dampen the surface. However, the best time to perform these operations is immediately after a rain. The damp surface will be softer for blading and will prevent the loss of fine particles. Because smoothing and reshaping are different operations, we will cover each operation separately. Let us begin by quickly looking at the equipment needed for smoothing. You will need a motor grater to smooth the surface. If the work must be done during dry weather, you will need a water truck to dampen the road surface. Smoothing is performed promptly when the road surface begins to get a little rough. The basic steps are, step one, place the traffic signs. Step two, determine and mark the limits for smoothing. Step three, blade the surface to form a windrow. Step four, spread the windrow. Step five, remove the traffic signs. Now that we have briefly covered the five steps for smoothing, we will look at each step in detail. Step one, place the traffic signs. Follow correct procedures for proper placement of the signs. They are important for everyone's safety. If this repair extends around a curve or over a hill, flagmen may be needed to direct traffic. See the IRF videotape on traffic control for more detailed information. Step two, determine and mark the limits for smoothing. To start, instruct your operator to smooth the road without destroying the crown. Repair only one half of the road at a time, even if a defect completely crosses the road so traffic can get by the work site. Work alongside the road where the repair is to begin and end. Step three, blade the surface to form a windrow. If the road surface is dusty, use the water truck to add moisture to prevent the loss of fine particles. To smooth the surface, start from the outside edge. Shift the blade to drag the surface irregularity. The top and bottom edges of the blade must be in the same vertical line. Adjust the position of the blade parallel to the road surface. Next, angle the blade between 30 and 45 degrees to the motor grader's axle. Now, shift the blade to place the windrow toward the center of the road. Do not run the motor grader's wheels over the windrow as it is being formed. The bottom edge of the blade should remove the high spots of the surface irregularities. It should not cut into the crust of the road surface. Work in passes about 200 meters long. Usually, one pass is sufficient to drag one half of the road. Step four, spread the windrow. Set the blade forward at the top. Angle the blade to pick up and spread the windrow from the center toward the edge of the road. Adjust the position of the blade parallel to the road surface. Spread the windrow evenly. Continue the smoothing on the other half of the road. The compaction of this material will be made by the motor grader and traffic. Add water as necessary for good compaction of the newly smoothed surface. Step five, remove the traffic signs. Watch for oncoming traffic and be sure all personnel are off the road. A road that has been improved by smoothing provides a good riding surface. Remember, there are five steps for smoothing earth and gravel roads. Step one, place the traffic control devices. Be sure to follow your approved procedures. Step two, determine and mark the limits for smoothing. Be sure the motor grader operator understands your instructions. Step three, blade the surface to form a windrow. Use the proper blading procedure for smoothing. Step four, spread the windrow. The spread material should be even. Step five, remove the traffic signs. Make sure all personnel and equipment are off the road. This completes the smoothing operation. Reshaping is performed when the proper crown has been lost. Also, there may be corrugations and ruts in the road surface, causing traffic to proceed very slowly over the rough surface. Schedule all ditches and culverts to be cleaned if necessary during the reshaping operation. Good drainage is essential for a long-lasting repair. The IRF videotapes on cleaning ditches and culverts will provide additional information. Patch major potholes and depressions before any reshaping activity. See the videotape on patching unpaved roads for more information. For reshaping, you will also need a rubber-tired roller in addition to the motor grater and the water truck. You can use a steel-wheeled roller if the rubber-tired roller is not available. You will use a camber board to check for the cross slope. Be sure to take shovels, rakes, and wheelbarrows to remove large rocks and other unsuitable material from the road surface. Let us quickly look at the basic steps for reshaping. Step one, place the traffic signs. Step two, determine and mark the limits for reshaping. Step three, blade the surface to form a windrow. Step four, spread the windrow. Step five, check the cross slope. Step six, compact the surface. Step seven, remove the traffic signs. Now that we have briefly covered the seven steps for reshaping, we will look at each step. Step one, place the traffic signs. Follow the same procedures used for smoothing. However, reshaping involves more personnel and equipment than smoothing. So use more caution while directing the work. Step two, determine and mark the limits for reshaping. To start, check the surface for major defects that will cause the road surface to be rough. Also, check the section where the road has been flattened. Make sure sufficient material remains to restore a smooth surface with a proper crown. Once again, mark where the repair is to begin and end. Step three, blade the surface to form a windrow. It is best to begin this step when the road surface is damp because the material will be easier to cut. To reshape the surface, start from the outside edge. If the road surface is very hard, use the scarifier to break it up. Be sure to remove large rocks and clay lumps. Set the blade to cut to the bottom of the surface irregularity. The bottom edge of the blade must be in front of the top edge. To obtain the proper cross slope, which is generally 4%, position the blade so the end near the center line is slightly higher than the other end. Next, angle the blade between 30 and 45 degrees to the motor grater's axle to form the windrow toward the center line of the road. Now, shift the blade to place the windrow inside or outside of the wheels. Lean the front wheels in the direction of the windrow to be formed to help counter side thrust on the blade. Do not run the motor grater's wheels over the windrow as it is being formed. Also, try to leave as much crust as possible. Do not mix the earth subgrade material with the surface material. Step 4, spread the windrow. Set, angle, and adjust the blade properly. Spread the windrow evenly from the center toward the edge of the road to form the proper cross slope. Continue to blade the surface and spread the windrow on the other half of the road. Do not leave material by the road that would cause poor drainage. Also, make transitions to railroads and bridges gradual. Step 5, check the cross slope. Use a camber board. The camber board measures the fall of the road surface from the center line to the edge. This is called the cross slope of the road. The camber board must have the same cross slope that you want for your road. For a 4% cross slope, the road surface from the center line to the edge must drop 4 centimeters for each meter. To check the cross slope on a straight section of road, place the camber board straight across the road with its shorter end toward the center line and check the bubble. If the cross slope is correct, the bubble should be centered in the camber board indicator. Repeat this check approximately every 30 meters. The proper crown should look like this. On a curved section of road, the cross slope should remain the same across the entire width of the road surface. No crown should be evident and the cross slope should look like this. Make the transitions between the curved and straight sections of the road gradual. To look like this, if the bubble is not centered, the cross slope is too steep or too flat. To correct the cross slope, blade and spread the material again. The proper cross slope is very important for good drainage. Step 6. Compact the surface. Before compacting, quickly test the correct moisture content of the material. Squeeze a sample in your hand. If it crumbles, it is too dry. Water must then be added to increase the moisture content. If the sample remains in a ball after you squeeze, the material has the proper moisture. This will help obtain good compaction. If the sample runs out between your fingers when you squeeze, it is too wet. It must be allowed to dry before compaction. When the material has the proper moisture content, compact the surface. Use a rubber-tired roller or a steel-wheeled roller. Start at the edge of the road, then overlap each pass one-third the width of the roller as you move toward the center. Make several complete passes across the surface to fully compact it. Do not destroy the crown by making a pass down the center line of the road. Step 7. Remove the traffic signs. Make sure all equipment is off the road and be careful of oncoming traffic. A reshaped road provides a smooth riding surface and allows water to drain properly. Remember, there are seven steps for reshaping earth and gravel roads. Step 1. Place the traffic signs. Be sure to follow your approved procedures. Step 2. Determine and mark the limits for reshaping. Work on one-half of the road at a time. Step 3. Blade the surface to form a windrow. You must use the proper blading procedure for reshaping. Step 4. Spread the windrow. The surface layer should be even and free of rocks and debris. Step 5. Check the cross-slope. You must obtain the proper cross-slope for proper drainage. Step 6. Compact the surface. Make sure it is thoroughly compacted. Step 7. Remove the traffic signs. Make sure the road is clear of personnel and equipment before removing the signs. Smoothing and reshaping provide good riding surfaces. Ensure proper drainage and extend the useful life of earth and gravel roads.