Sight triangles shall be required at each quadrant of an intersection of streets, and streets and driveways. The area within sight triangles shall be either dedicated as part of the street right-of-way or maintained as part of the lot adjoining the street and set aside on any subdivision or site plan as a sight triangle easement. Within a sight triangle, no grading, planting or structure shall be erected or maintained more than 30 inches above the centerline grade of either intersecting street or driveway or lower than eight feet above their centerlines including utility poles but excluding street name signs and official traffic regulation signs. Where any street or driveway intersection involves earth banks or vegetation, including trees, the developer shall trim such vegetation and trees as well as establish proper excavation and grading to provide the sight triangle. The sight triangle is that area bounded by the intersecting street lines and a straight line which connects “sight points” located on each of the two intersecting street lines the following distances away from the intersecting street lines: arterial streets at 130 feet; collector streets at 60 feet; and primary and secondary and local streets at 35 feet. Where the intersecting streets are both arterial, both collectors or one arterial and one collector, two overlapping right triangles shall be required formed by connecting the sight points noted above with a sight point 35 feet on the intersecting street. Any proposed development requiring site plan approval shall provide sight triangle easements at each driveway with the driveway classified as a local street for purposes of establishing distances. The classification of existing and proposed streets shall be those shown on the adopted Master Plan or as designated by the Planning Board at the time of the application for approval for a new street not included on the Master Plan. Portions of a lot set aside for the sight triangle may be calculated in determining the lot area and may be included in establishing the minimum setbacks required by the zoning provisions.