There are two reasons why a concrete driveway must be poured in sections - first, if it is more than 20 feet long, and second, if the driveway surface will be crowned, that is, it will be higher in the center and on the side closest to the house foundation than on the far side. Follow this procedure for sectioning a concrete driveway as it is being poured.
Step 1 - Build the Concrete Forms
Place wood stakes in the ground every 3 feet along each outer edge of the driveway, so the tops are 6 inches above the ground. Tie string between the stakes at 4 inches above the ground so they are level, following the ground contours if your driveway slopes down to the roadway. Curve the stakes outward on each side where the driveway meets the road curb, to allow for easier entry and exit.
Cut the plywood panel in half lengthwise and curve 1 section for each side of the driveway entry, nailing it to the stakes. Set the 2 by 4 boards in the ground inside the line you formed with the stakes and string, and nail the boards to the stakes with two-headed nails. Apply motor oil with the paintbrush generously to the boards where they will meet the concrete, to enable easier removal after the concrete sets firmly.
Step 2 - Mark the Sections
From the garage toward the road, mark the first 10-foot long section with a crossboard of 2x4 planks, the same width as the driveway section, fit them between the two parallel boards down the driveway sides, and make sure the crossboard is at 90 degrees to the sides. Check it is level by resting a carpenter's level on top. You will move this crossboard to mark the second section, so do not nail it in place. Drill two holes near the top of this board, one on each side, 1 inch in diameter. Oil it well so you can slip it out more easily later. Add the reinforcing bars every 3 feet, raised on stones or bricks about 2 inches above the driveway base.
Step 3 - Pour the Concrete into the Forms
With at least two helpers, be ready to level the concrete as it is poured. Use a 10-foot plank with one person on each end, moving it in alternating angles across the wet concrete so it is level to the top of the form boards. Scoop out the excess concrete and move it to the next section. Finish the first section with a bull float, to pop bubbles out of the concrete, then trowel and sweep its top to make a ridged surface for better traction. Move the crossboard to the end of the second section and repeat the pouring and leveling process.