People Friendly Streets - Roundabouts


Constructing modern roundabouts are the simplest method of converting a vehicle-orientated street to a people friendly street provided they are designed using the low speed in, low speed out, philosophy rather than the low speed in/high speed out philosophy. Not only does a well-designed roundabout lower vehicle speeds they substantially reduce the crossing distances for pedestrians ad reduce the complexity of pedestrian crossings by reducing the vehicle to pedestrian conflicts to one per pedestrian crossing.

Modern roundabouts are more efficient than signalized intersections by up to 30 percent, which provides the opportunity to reduce the number of vehicle lanes. Alternate Street Design, P.A. has helped to conceive and assist in the redesign of a number of streets where the number of through lanes has been substantially reduced such as La Jolla Boulevard, San Diego, 5 to 2 lanes and Prairie Star Parkway, Lenexa, KS, six lanes to four and College Street, Asheville, NC five lanes to two lanes.

Crash reduction at modern roundabouts is outstanding. According to the Insurance Institute for Highway Safety, fatal crashes are reduced by 90 percent; injury crashes by 76 percent and all crashes by 39 percent. Roundabouts that I designed have very few crashes.

In keeping with latest trends, roundabouts typically have a smaller carbon footprint, less pollution and fuel consumption, less water run-off and enable landscaping within the central island reducing the overall area of asphalt.

In addition to al of the above roundabouts when well-landscaped beautify an intersection and enhance the neighborhood, a commercial of retail area or can create a gateway to all of the aforementioned.


Top: Hilton Head, SC

Second: Twin Roundabouts, Melbourne, Australia

Third: Multi-lane roundabout on two, one-way streets, Lacey, WA

Fourth: Downtown, Sarasota, FL

Top Right: Port St Lucie, FL