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 commonly yielded to traffic entering the circle causing traffic jams within the circle. While traffic circles fell out of use in the US many European countries modified the design and eventually created the modern roundabout. The modern roundabouts have since gained renewed interest in the US because of the safety benefits, high capacity, traffic calming effect, 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 - Keene
- How to Drive a Multi-Lane Roundabout Flyer - Lee (New 9/30/15)
- 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 at DW Highway - 1 | 2 | 3
- Nashua - NH 130 (Broad Street) at Nashua North HS (by City)- 1 | 2 | 3
- Meredith - US 3 at NH 106 (Parade Road)- 1 | 2 | 3 | 4
- Plymouth - US 3 at NH 175A - 1 | 2 | 3 | 4
- Hanover - NH 10 (built by Town) - 1 | 2 | 3 | 4
- Keene - Court Street at Cheshire Medical Center (by City)- 1 | 2
- Keene - NH 101 at Winchester Street - 1 | 2 | 3 | 4
- Keene - Main Street at Winchester Street (by City) - 1 | 2 | 3
- Peterborough - NH 101 at shopping center - 1 | 2 | 3
- Rye - NH 1A at Elwyn Road (Foye's Corner) - 1 | 2 | 3
Design Information
- NH Supplemental Design Criteria
- Roundabouts: An Informational Guide (FHWA, 2000)
- Roundabouts: An Informational Guide, 2nd Edition (FHWA, 2010)
- NCHRP 572:Roundabouts in the United States (TRB, 2007)
- Roundabout Operational Analysis (from NCHRP 572)
- Roundabout Operational Analysis Worksheet (by NHDOT based on NCHRP 572)
- RODEL Settings
Private Roundabout Web Site Links
Additional Web Site Links