This question should be answered from the perspective of zoning regulations, where a minimum distance is typically required between a curb cut and an intersection (usually about 50 feet or less, depending on the jurisdiction).
Even if we accept the rule-of-thumb approach referenced in the Site Planning and Design Handbook (2nd ed., p. 206), the 100-foot standard is not applicable to this diagram. That requirement applies specifically to offset intersections, which is not the condition shown here.
As the handbook states: “Intersections of two or more streets should be carefully designed to provide adequate sight distance as well as smooth traffic flow. Grades at intersections should be kept to 3 percent or less. On local streets, a clear sight triangle of no less than 50 ft is required. When local roads dictate an offset intersection, at least 100 ft should be provided between intersections.”
Therefore, applying the 100-foot spacing requirement in this case would be incorrect. In fact, in a typical small urban block with narrow lots, such a requirement would make it difficult or impossible for corner lots to provide adequate vehicular access and parking.