A method of employing a safe and effective flexible plastic curb and gutter. The method of installing a curb along the side of a road having a lower layer prior to laying a top layer of asphalt on the road comprises providing elongated curb strips each having i) a horizontal holding side portion having spaced openings cut therealong; and, ii) a uniformly continuous upright trough portion having a lower edge portion continuously attached to the outer edge of the horizontal side portion. An upper edge portion of the upright trough portion is adapted to extend above the upper layer of asphalt so that water running off the road is channelled along an inner side of the upright trough portion. The horizontal holding side portion of the elongated strip is seated along and parallel to an outside edge portion of the lower layer so when the top layer of asphalt is laid thereon adhesion between the layers through the openings therethrough hold the elongate curb strip in position.
