The Highway Corridor Overlay (HCO) District shall be superimposed over the Official Zoning Map, and shall consist of those lots directly abutting specific thoroughfares. The underlying zoning district shall hereafter be called the base district. When land is proposed to be developed within the boundaries of the Highway Corridor Overlay District, such development shall meet the requirements of the base district, as well as the requirements of the Highway Corridor Overlay District.