(a) All changes of grade shall be connected by vertical curves of a minimum length in feet equal to twenty times the algebraic difference in the rate of grade for arterials and industrial streets; for collector and local streets, fifteen times.
(b) Minimum vertical visibility shall conform to Ohio Department of Transportation regulations in effect on the date of the approval of the preliminary plat.
(c) No street grade shall be less than one-half percent (0. 5%) and in no case shall a street grade be more than three percent (3%) within 100 feet of an intersection.