City of Rochester

NH 125 at Amarosa Drive Intersection Improvements

Rochester, NH

Project Summary

Seeking to encourage development and provide quality employment within the city, Rochester partnered with Sig Sauer, Inc. to develop a new manufacturing center at 7 Amarosa Drive adjacent to Milton Road (NH 125). The development, which will add up to 475 new jobs within the next five years, is also expected to generate significant traffic, especially during shift changes. Making things more challenging, the signalized intersection of Amarosa Drive with NH 125 (a commercial arterial with 8,000 vehicles per day) is significantly skewed and creates numerous safety and operational issues that will need to be overcome to ensure the facility can be a success. As Hoyle Tanner was already evaluating potential improvements to this intersection through the City’s Capital Improvement Program (CIP), the City expanded our partnership to perform design engineering services for offsite improvements needed to safely and efficiently deliver people and materials to this important site. 

The backbone of every successful transportation improvement project is a comprehensive planning study. Our Team’s initial efforts included coordination of traffic data collection, evaluation of anticipated site trip generation, a five intersection corridor traffic capacity analysis, and review of network crash history over the last three years. The results of the traffic analysis indicate that an increase in capacity is required to provide an acceptable Level of Service (LOS) during opening and future year conditions. To provide these LOS improvements, we evaluated three conceptual intersection alternatives which included: a new traffic signal with a second northbound & southbound travel lane and improved approach geometry, a single lane roundabout with geometry designed for optimized traffic operations, and a second roundabout designed to minimize impacts to abutting properties. Each alternative is anticipated to require approximately 1,500 linear feet of roadway improvements to implement. Conceptual opinions of probable construction cost, a technical memorandum, and a public outreach program to convey and build consensus will support these engineering efforts. 

It is anticipated that a single lane roundabout will be the preferred alternative to improve intersection capacity and safety and support the planned Sig Sauer development. Preliminary and final design of the project is planned to be performed in 2022 with construction in 2023 or 2024. 


  • Final Design 
  • Intersection Analysis 
  • Study 
  • Signal Warrant Analysis 
  • Conceptual Design 
  • Permitting 
  • Utility Coordination 
  • Traffic Control/Management 

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