The plans and specifications must provide for improvement of the designated streets or construction of skyways in a manner designed for the free movement, safety, convenience, and enjoyment of pedestrians, whether or not part of the mall is made available for emergency or     other permitted vehicles. A mall improvement may provide for and include space for seating, cafe tables, shelters, trees, flower plantings, sculptures, newsstands, telephone booths, traffic signs, kiosks, fire hydrants, streetlighting, ornamental lights, trash receptacles, display cases, marquees, awnings, canopies, overhead and underground radiant heating devices, walls, barriers, and all other fixtures, equipment, facilities, and appurtenances as will in the governing body’s judgment enhance the free movement, safety, convenience, and enjoyment of pedestrians and benefit the adjoining properties and the central business district and the city. Sidewalks may be constructed of concrete, bricks, asphalt tiles, blocks, granite sets, or other materials or combinations of materials as the governing body may approve. The governing body may alter any roadway to be kept and maintained in the mall, may cause any street vaults to be reconstructed or removed, may construct crosswalks at any point within or at the ends of blocks, and may cause any roadway to curve and meander within the limits of the street, if determined desirable to enhance the usefulness or appearance of the mall, regardless of any nonuniformity of street width or any curve or absence of curve in the centerline of the street. A skyway may be heated or unheated and may include any fixtures, equipment, facilities, and appurtenances the governing body determines will enhance the free movement, safety, convenience, and enjoyment of pedestrians and benefit the adjoining properties and the central business district and the city.