Barricades are used for a wide variety of reasons, including rerouting traffic, whether it's automobiles or foot traffic. You see them in public places when many people converge in one location such as a rock concert. At river markets and festivals, they are used to inform people where they can find restrooms or first aid. Building your own barricades is something the do-it-yourself consumer can tackle with confidence. They are constructed much like sawhorses. In those cases, the cross member of the sawhorses usually dons vinyl barricade tape appropriate for the need.
Place one of the pieces of 24-by-36-by-3/4-inch treated plywood on a worktable. Position it on the table so the 36-inch side is parallel with the front of the worktable. Measure from the left-hand corner and make marks on the 36-inch side at 15 and 21 inches.
Set the straightedge on the 15-inch mark and the corner to your left on the opposite 36-inch side. Draw a line from the mark to the corner with a pencil. Repeat this with mark at 21 inches and the corner to your right.
Cut the lines with a circular saw. Turn the piece around so the opposite 36-inch side is closest to the front edge of the worktable. Measure from the corner on your left and make a mark on the 36-inch side at 9 inches. Repeat this from the corner on your right and then mark the center of the 36-inch side.
Put the framing square on the center mark and draw a 9-inch line. Hold the long leg of the framing square on the line so the corner of the framing square is at the end of the 9-inch line and the short leg of the framing square goes to the right. Draw a 3-inch line to your right.
Flip the framing square over and draw a 3-inch line to your left. Set the straightedge at the end of the line on your left and the 9-inch mark on the 36-inch side of the plywood and draw a line.
Repeat this with the other end of the 6-inch line and the other 9-inch mark. Cut the lines with a jigsaw. Turn the plywood around again.
Mark the center point of the 6-inch side of the plywood and then mark 3/4 inch in both directions of the center mark. Put the framing square on the marks and draw a 10 1/2-inch line from each mark. Connect the ends of the two lines and then mark each line at 4 1/2 inches from the 6-inch side. Connect those marks with a line, resulting in a rectangle.
Drill a 3/8-inch hole inside the 1 1/2-by-6-inch rectangle. Slip the jigsaw blade into the hole and cut out the rectangle. Set this piece on the other piece of 24-by-36-by-3/4-inch treated plywood and trace its pattern onto it. Cut the second piece to look like the first. Insert the 2-by-6-by-48-inch lumber into the rectangle cutout and lean the A-frames toward the center.