PRINCIPLE NO. 4 Minimize Cul-de-Sacs
Minimize the number of residential street cul-de-sacs and incorporate landscaped areas to reduce their impervious cover.
The radius should be the minimum needed for emergency and maintenance vehicles.
Alternative turnarounds should be considered.
Notes:
Many communities require the end of cul-de-sacs to be 50 to 60 feet in radius, creating large circles of impervious cover that could double as helicopter landing pads. There are several different options for reducing the total amount of impervious cover created by traditional cul-de-sacs. One option is to reduce the radius of the turnaround bulb. Several communities have implemented this successfully and the smaller radii can range from 33 to 45 feet. Secondly, since most vehicles only use the outside of a cul-de-sac when turning, a second option is to create a pervious island in the middle of the cul-de-sac creating a donut like effect. Loop roads and hammerheads can also be used in lieu of traditional cul-de-sacs.