The Big Dig's Hidden Legacy: How Boston Learned to Bury Its Mistakes

For almost half a century, a highway stood between Boston's North End and the rest of downtown. The elevated Central Artery carried Interstate 93 on steel columns, and the streets beneath it lived in its shade and its noise. Its demolition was completed in 2004. Along its old route, the Rose Kennedy Greenway now runs for a mile and a half through a chain of parks.

The Big Dig, officially known as the Central Artery/Tunnel Project, is typically remembered for its cost overruns and construction delays. But nearly two decades after its completion, a different story emerges—one of urban healing, unexpected consequences, and the complex relationship between infrastructure and community.

The Weight of Concrete

In 1954, when the Central Artery first opened, it was hailed as a marvel of modern engineering. The elevated highway carried Interstate 93 directly through downtown Boston, connecting the suburbs to the city center with brutal efficiency. What planners didn't anticipate was how completely it would sever Boston's historic neighborhoods from each other and from the harbor.

The North End, home to Italian-American families for generations, found itself cut off from downtown. Chinatown was squeezed between highways and rail lines. The waterfront, once the city's economic heart, became an isolated industrial zone invisible to most residents.

By the early 1990s, the elevated highway carried upwards of 200,000 vehicles a day through a corridor designed for 75,000. Traffic crawled for more than ten hours every day, and the accident rate ran four times the national average. The structure itself was deteriorating.

Going Underground

The solution proposed in 1985 seemed impossibly ambitious: bury the entire Central Artery in a tunnel system beneath the city, remove the elevated highway, and create new parkland on the surface. The project would require digging beneath Boston's harbor, threading tunnels around subway lines and building foundations, and keeping traffic flowing throughout construction.

It would become the most expensive single highway project in the United States.

The technical challenges were staggering. Engineers had to freeze the ground to dig beneath the railroad tracks at South Station. They built "slurry walls": narrow trenches held open by a bentonite slurry, which was then displaced by reinforced concrete to form the tunnel walls. The entire project required removing 16 million cubic yards of soil, enough to fill a stadium to the rim sixteen times.

The Human Cost of Ambition

But the Big Dig's real cost wasn't measured in dollars or cubic yards of dirt. It was measured in the sixteen years that construction dominated daily life for hundreds of thousands of Bostonians.

The Greenway, as envisioned, would connect Boston Common to the harbor with an unbroken chain of parks. But during construction, the area became a maze of fences, equipment, and excavated dirt. Small businesses closed. Residents moved away. Entire blocks became construction zones for years at a time.

The financial costs spiraled from an initial estimate of $2.6 billion to a final tab of nearly $15 billion, or about $24 billion once interest on the debt is counted. In April 2000 the overruns forced the Turnpike Authority's chairman, James Kerasiotes, from office. Federal oversight intensified. Boston became synonymous with infrastructure excess.

What Rose from the Ruins

When the elevated highway came down in 2004, Boston didn't just remove a barrier—it created a laboratory for urban regeneration. The Rose Kennedy Greenway stretches 1.5 miles from Chinatown to the North End, connecting neighborhoods that had been divided for half a century.

The transformation was soon visible. Assessed property values in the Greenway district, which had grown far more slowly than the central business district's in 2000–2005, caught up in 2005–2009 as the highway came down and the parks opened. The North End, cut off for half a century, became an easy walk from downtown again. Removing the highway opened new views of the harbor, including from Faneuil Hall Marketplace.

The park hosts farmers markets, festivals, and art installations. Food trucks line the pathways during lunch hours. Families from Chinatown picnic next to business workers from the Financial District. The North End's elderly Italian residents sit on benches watching children from every corner of the city play in the fountains.

The Unintended Consequences

But the Big Dig's legacy is more complex than its boosters anticipated. The same forces that brought new life to previously divided neighborhoods also brought displacement and gentrification.

The North End, once a working-class Italian enclave, now has some of the highest rents in Boston. Chinatown faces pressure from developers seeking to capitalize on the area's improved connectivity. Long-time residents who endured the construction years find themselves priced out during the recovery.

This tension reflects a broader challenge in urban policy: infrastructure projects intended to heal communities can also transform them beyond recognition. The Big Dig removed a physical barrier, but it couldn't address the economic forces that reshape neighborhoods once they become desirable again.

Lessons from Below

Twenty years later, what can other cities learn from Boston's buried highway?

First, that infrastructure budgets can underestimate community and social costs. The Big Dig's price tag, nearly $15 billion and about $24 billion with interest, included mitigation for neighbors and businesses, but it does not capture sixteen years of disrupted lives and lost trade.

Second, that removing highways creates opportunities but doesn't guarantee outcomes. The Rose Kennedy Greenway succeeded because of sustained community engagement, dedicated funding for maintenance, and programming that serves diverse populations. Without those elements, reclaimed land can become vacant lots or luxury development sites.

Third, that urban healing takes time. The Big Dig's construction began in 1991, the elevated highway came down in 2004, and the Greenway opened in 2008 and kept adding features for years afterward. Development took years longer still to reorient itself toward the new parks.

Finally, that infrastructure decisions have consequences that last generations. The Central Artery divided Boston for fifty years. Its removal has been reshaping the city for twenty years more. The children playing in Greenway fountains today will inherit whatever comes next.

The Deeper Dig

Boston's Big Dig represents both the potential and the perils of ambitious infrastructure projects. It proved that cities can successfully remove highways that no longer serve their communities. It demonstrated that reclaiming urban land can catalyze broader neighborhood revitalization.

But it also revealed that the communities most affected by infrastructure often have the least control over its transformation. The residents who endured decades of highway noise and construction dust may not be the ones who benefit from the parks and property value increases that follow.

The real legacy of the Big Dig isn't the tunnels beneath Boston or even the parks above them. It's the recognition that infrastructure is never just about moving traffic efficiently from point A to point B. It's about how communities live, grow, and change together.

Standing on the Greenway today, watching children play where highway traffic once roared, it's easy to see the project as an unqualified success. But the full story—like the tunnels beneath the city—runs deeper than what's visible on the surface.

The Big Dig's Hidden Legacy is part of Atlas Urbium's series on highway removal and urban transformation. Read more in Urban Wounds, on the expressway that split New Orleans' Tremé.

References:

• Flint, Anthony. "10 Years Later, Did the Big Dig Deliver?" The Boston Globe Magazine, 2015.
• HR&A Advisors for the Boston Redevelopment Authority. "Rose Kennedy Greenway: Creating Long-Term Value." 2010.
• Massachusetts Department of Transportation. "The Big Dig: Project Background" and "The Big Dig: Facts and Figures."
• Rose Kennedy Greenway Conservancy. "Annual Report 2023."

Further Reading:

• Rose Kennedy Greenway - Wikimedia Commons - Extensive photo documentation of the Greenway transformation
• Big Dig - Wikimedia Commons - Historical photos and construction documentation
• Rose Fitzgerald Kennedy Greenway - Wikipedia - Comprehensive overview of the park's development and features
• Congress for New Urbanism - Boston Case Study - Analysis of the Big Dig as highway removal precedent