Boundary lines. The zone boundary lines are intended generally to follow straight lines, existing lot lines, center line street railroad rights-of-way and waterways and development boundaries as indicated on the Zoning Map; but where a boundary line does not coincide with such line, its location is indicated on said map by means of figures expressing distance in feet from a street line. In case of uncertainty as to the true location of any zone boundary line, the determination thereof shall lie with the Joint Land Use Board of the Borough of Dumont.