River Birch Marketplace Traffic Calming

TFMoran designed a modern roundabout as the solution for access to the new River Birch Marketplace on NH Route 101 just west of Peterborough center. It is one of only a handful in the state, and the first to be permitted on a major state highway for access to a commercial development. Completed in November 2008, the roundabout will handle about 15,000 vehicles per day, many of which will be accessing the new marketplace.

The modern roundabout differs significantly from the traditional traffic circle prevalent on older New England highways. The main difference is travel speed–whereas the older designs can be traveled at speeds of 35 mph or more, the modern roundabout is designed to slow traffic to 20 or 25 mph. The slower circulating speed makes it easier for vehicles to enter the stream of traffic and keep it moving, which can help reduce delays and lengthy queues associated with signalized intersections. Because of this, roundabouts also reduce air pollution associated with congestion. These are among the primary reasons that the Peterborough Selectmen and Town Planners rallied in favor of a roundabout versus a traffic light.

  • Client: Town of Peterborough
  • Services: Traffic Engineering