Route 128 Add-A-Lane – Bridge I

Benesch provided complex bridge and highway design services to the Massachusetts Department of Transportation for this key one-mile stretch of interstate highway, which carries approximately 200,000 vehicles daily. Services included the preparation of plans, specifications, estimates and environmental documentation, as well as attendance at public hearings for permitting.

Benesch designed replacements for the following bridges:

• Route 128/I-95 over Neponset River
• Route 128/I-95 over MBTA/Amtrak Railroad
• Route 128/I-95 over University Avenue

Benesch also designed one mile of a major highway widening—from three lanes to five lanes in each direction—including NB and SB auxiliary lanes and a major highway split at Routes I-93 and I-95.

The highway widening required drainage design and water-quality BMPs for five extended detention ponds and two water-quality swales. Mechanically stabilized earth retaining walls were utilized to minimize impacts to adjacent critical ACEC wetlands. Coordination with and presentations to local conservation commissions were also required.

Benesch also provided traffic management design for six complex construction phases. The project required significant railroad coordination with Amtrak and the Massachusetts Bay Transportation Authority.