Abstract: Various implementations include a mat having a lower surface and first and second edge portions that define at least a portion of a perimeter of the mat. The mat also includes a plurality of ribs that extend away from the lower surface of the mat for contacting the floor. Each rib has a longitudinal axis that extends between ends of the rib, and at least a portion of the plurality of ribs includes one or more branches that extend transversely to the longitudinal axis and are axially spaced apart from each other. The ribs are spaced apart from each other over the lower surface such that adjacent ribs define a valley therebetween. Water and/or debris can flow through the valleys. In addition, the longitudinal axis of each rib intersects the first and second edge portions of the mat at angles that are greater than 0° and less than 90°.