Case Study: Delay from Design Changes on Boston Central Artery Project (Boston, MA, 2008)

Project Overview
• Name: Boston Central Artery/Tunnel Project (“Big Dig”)
• Location: Boston, Massachusetts
• Year: 2008 (Construction Phase)
• Project Size: $14.6 billion total project (ongoing phases)
• Scope: Complex highway tunneling and bridge construction in urban environment
• Lead Agencies/Contractors: Massachusetts Turnpike Authority /

Category of the Issue, Problem, or Challenge
• Design Changes
• Project Delay

Summary of the Issue, Problem, or Challenge
Multiple mid-construction design revisions to address unforeseen site conditions and community requests caused schedule disruptions.

Root Cause Analysis

• Incomplete Early Design Work: Gaps in initial engineering surveys and designs.
• Community Impact Considerations: Additional features added per public input mid-construction.
• Regulatory Changes: New safety and environmental requirements introduced.
• Coordination Complexity: Managing changes across multiple contractors and subcontractors was challenging.

Impacts Due to the Issue, Problem, or Challenge

• Delay of approximately 12 months in several project segments.
• Significant cost increases beyond original budget.
• Increased complexity in construction sequencing and logistics.

Corrective Actions Taken

1. Strengthened upfront design efforts and peer reviews.
2. Improved change management procedures with defined workflows and approvals.
3. Increased stakeholder engagement during design phases to reduce late changes.
4. Established integrated project delivery methods for better coordination.

Lessons Learned

• Comprehensive early design reduces later changes and delays.
• Clear change management protocols are essential.
• Stakeholder input must be gathered early to avoid costly mid-project revisions.

Audit & Prevention: Project Control Questions to Ask on Future Projects to Help Control the Situation

• Are designs fully vetted before construction starts?
• Is there a structured process for managing design changes?
• Are stakeholders engaged early and meaningfully?