In order to promote a living environment free from the excessive noise produced by vehicular traffic upon Interstate 35 the developer, with approval by the City Planning and Zoning Commission and the City Council, shall incorporate additional plantings and proper acoustical site design techniques to reduce the negative impact of highway noise. As part of the final site development proposal for that area of the PUD adjoining the Interstate 35 right-of-way and where it is shown on the sketch plan that sound attenuation measures are to be incorporated, sufficient landscape plantings, architectural or engineering barriers shall be provided; predominate plantings if used shall be of evergreen type, shrubs and trees so as to assure year round effectiveness; density and height of plantings or barriers shall be such as to provide maximum attenuation. The incorporation of sound attenuation measures shall be the responsibility of the developer and made a part of plat improvements when affected properties are subdivided. (Ord. 671, 5-11-1981)