NHDOT / The Louis Berger Group

I-93 Salem to Manchester Widening Exit 1 Interchange

Salem, NH

Project Summary

The C and D contracts were a component of the southern segment of the overall corridor program to widening I-93 corridor from the Massachusetts border north approximately 9 miles just beyond the Windham Weigh Stations area north of the Exit 3 interchange. These contracts included highway, bridge, ramps, ancillary roads, drainage, traffic control, environmental mitigation, Right-of-Way, sound walls, and retaining wall designs to make improvements required to meet the forecasted traffic demands and address the safety along this vital corridor. The design proposed extensive reconstruction of the state highway and Exit 1interchange. 

Our Federal and State funded Exit 1 Interchange Improvements design contract involved:  

  • Realignment of highway ramps with Rockingham Boulevard and South Policy Street work; 
  • Coordinated construction sequencing to facilitate the replacement of seven of the existing “Red List” bridges with five new or rehabilitated structures; 
  • Final design of a sound abatement barrier adjacent to existing residences;  
  • Unique culvert solutions for maintaining stream flow through the interchange; 
  • Develop and accommodate innovative stormwater drainage and treatment alternatives; 
  • The requirement to simultaneously maintain both the mainline and ramp traffic operations while proposing a highly aggressive two-year construction operation; 
  • At the request of the client, the need to phase the interchange improvements into two separate construction contracts advertised three years apart from each other. 

Project Cost: $22,245,000 for the entire Contract C. with the Ramps only costing $14,200,000 of that. The Contract D cost was $31,000,000 with the Ramps costing $1,500,000 of that amount. 


    • Project Management 
    • Highway Design 
    • Alternatives Analysis  
    • Drainage Analysis and Design 
    • Culvert Design 
    • Stormwater Management 
    • Utilities  
    • Traffic Control 
    • Retaining Walls 
    • Cost estimation 



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