The job duties of a general laborer vary. They may include cleaning and preparing a job site, loading and delivering materials, and using a variety of tools and machines. Laborers set up and take down ladders, scaffolding, and other temporary structures. They help carpenters, masons, and other specialized contractors. At road construction sites, general laborers may control traffic. They set up markers, cones, and barricades and may flag vehicles to control the flow of traffic. General laborers must have physical strength, hand-eye coordination, and endurance. The ability to understand and communicate information is also essential.