The following requirements shall apply to special street types:
(a) Permanent dead-end streets shall not be permitted. Temporary dead-end streets shall be permitted only as part of a continuing street plan and only if a temporary turnaround satisfactory to the Planning Commission in design is provided.
(b) Dedication of new half-streets shall not be permitted. Where a dedicated or platted half-street exists adjacent to the tract being subdivided, the other half shall be platted.
(c) Alleys shall not be approved.