Project Information > Roundabouts
In 1903 the Columbus Circle opened in New York City, this was the first traffic circle to be built in the United States. Traffic Circles were constructed in New Hampshire from about the 1940’s to 1960’s. They fell out of favor beginning in the 1960’s because they relied on high speed merging of traffic and the traffic in the circle yielded to traffic entering causing traffic jams. While traffic circles fell out of use in the US many European countries modified the design and eventually created the modern roundabout. The modern roundabout has since gained renewed interest in the US because of the safety benefits, high capacity, traffic calming affect, and aesthetic value they can bring to an intersection.
The information below is intended to answer some common questions and provide additional information to communities and the general public as to what roundabouts are and how they operate.
Also included are NHDOT roundabout design guidelines that supplement the FHWA Roundabout Guide.
Brochures
- How to Drive a Single Lane Roundabout Brochure
- How to Drive a Multi-Lane Roundabout Flyer
- FHWA: Your Community Deserves Less
- FHWA: Roundabouts - A Safer Choice
Simulations
Informational Posters
- Roundabout Features
- Roundabout Benefits
- Roundabouts in New Hampshire
- Roundabout Design Vehicles
- Bikes and Peds in Roundabouts
- Roundabouts vs. Traffic Circles
Photos of Roundabouts in New Hampshire
- Nashua - Main Street - 1 | 2 | 3
- Nashua - Broad Street - 1 | 2 | 3
- Meredith - US 3 at Parage Road - 1 | 2 | 3
- Plymouth - US 3 at NH 175A - 1 | 2 | 3
- Hanover - NH 10 - 1 | 2 | 3 | 4
- Keene - Court Street - 1 | 2
- Keene - NH 101 at Winchester Street - 1 | 2 | 3
Design Information
- NH Supplemental Design Criteria
- Federal Highway Admin: Roundabout Guide (2000)
- Roundabout Capacity Worksheet
- NCHRP 572: Roundabouts in the US
- RODEL Settings
Private Roundabout Web Site Links
Additional Web Site Links