what is the minimum diameter of a cul-de-sac at the end of a dead end road?

Answer 1

Dead-end streets and cul-de-sacs generally are regulated by the rules and regulations governing the subdivision of land that are adopted by the local planning board. Cul-de-sac regulations and standards, including those listed below, must be consistent with the purposes of subdivision controls stated in enabling legislation. These purposes generally include promoting general safety, convenience, and health and welfare; ensuring sanitary conditions; providing roadways that are safe and convenient for travel; securing safety in case of fire, flood, panic, and other emergency; and securing adequate provision of municipal services.

Diameter of cul-de-sac
Eighty-foot diameter, 50 feet of which is free of parked cars (Planning the Neighborhood); 90-foot diameter (Planning Design Criteria, Site Planning Standards, Control of Land Subdivision, Cost-Effective Site Planning; the National Fire Protection Association - Code 1, Section 1.1.1.10—requires access for fire apparatus when the Street is more than 300-feet long); 100-foot diameter (The Community Builders Handbook and “The Cul-de-sac Pros and Cons” in the ASPO Newsletter, American Society of Planning Officials, Chicago, Ill., September 1955).

Common practice is to require a 90-foot diameter, paved. The rationale for these standards is that older fire equipment and garbage trucks may have a turning radius of only 50 to 55 feet. New fire equipment generally has a smaller turning radius. Nevertheless, in a northern climate, where snow may be plowed to the side of the paved area, the larger diameter should still be required.

Answer 2

There is no "standard" universal. Every city will have it's own code. Can't answer the question without knowing the city or governing jurisdiction.

Answer 3

Guess you didn't like my other answer. Sorry. bout that.