Walk-behind concrete saws have wheels that support the saw and allow the worker to push the saw in a straight line to cut inlay lines and trenches in roads, sidewalks, and other concrete surfaces. They are also used to create stress lines when pouring and setting concrete. Corded walk-behind concrete saws are used indoors and outdoors. Gas-powered concrete saws are used outdoors in well-ventilated areas and are slightly more powerful than corded saws.