America's 29 most expensive megaprojects, ranked

Incredible megaprojects that cost billions

America doesn't do megaprojects by halves, investing years, sometimes even decades, and billions of dollars in bridges, railroads, airports, and more.

From icons of infrastructure such as the Golden Gate Bridge to modern marvels like the replacement Yankee Stadium, click or scroll on to discover some of America's most expensive public and private construction projects, ranked by total cost.

Project costs have been adjusted for inflation to show what they would cost in today's money.

29. Golden Gate Bridge: $814 million

Measuring more than 4,200 feet long, San Francisco's Golden Gate Bridge was completed in 1937 and promptly became the world's longest suspension bridge, a title it retained until 1964.

This amazing feat of engineering cost $35 million in 1937, which equates to $814 million in today's money. With the exception of the Sausalito Lateral approach road (now known as Alexander Avenue), no state or federal funding went into building the iconic structure.

28. Wekiva Parkway: $1.7 billion

Part of the Central Florida Beltway, the Wekiva Parkway (also known as Florida State Road 429) opened in January 2024 after more than a decade of construction. The total cost was $1.6 billion, or $1.7 billion in today's dollars.

The 25-mile-long highway passes through the environmentally sensitive Wekiva River Basin, adding to the complexity and expense of the work. Most of the project was financed by tolls on the new highway. 

=26. Extension 470: $2.7 billion

Extension 470, more commonly known as E-470, is a 47-mile-long toll road that curves around the eastern edge of the Denver metropolitan area in Colorado. 

Built in sections and completed in 2003, E-470 cost $1.5 billion, or about $2.7 billion in today's dollars. It's one of America's first privately built, owned, and operated toll roads.

=26. First Transcontinental Railroad: $2.7 billion

Completed in 1869, the First Transcontinental Railroad spanned 1,912 miles, connecting America's rail network from Omaha, Nebraska, to Sacramento, California. 

Two companies took on this massive undertaking: the Union Pacific built westward, and the Central Pacific worked eastward, with the line meeting in Utah.

Compensation included land rights and government bonds, so no reliable figures exist for the railroad's exact cost. One estimate puts the total at around $112 million, the equivalent of $2.7 billion today.

=24. Hoover Dam: $2.8 billion

Another construction triumph of the Depression Era, the Hoover Dam was built between 1931 and 1936 for $49 million. Its power plant and generators cost an additional $71 million, bringing the total to $120 million. That's around $2.8 billion in today's money.

In addition to providing thousands of jobs over the decades, the colossal dam is a key flood control safeguard and a major supplier of hydroelectric power in the region. In fact, sales of electricity generated by the Hoover Dam had paid back its construction cost, including interest, by 1987.

=24. Alaska Highway: $2.8 billion

The Alaska Highway was completed in 1942, a remarkable achievement given America was at war at the time.

The final bill for the 1,700-mile highway was $138 million, the equivalent of $2.8 billion today. The grueling project required a crew of more than 25,000 men to work seven days a week.

23. I-95 New Haven Harbor Corridor Reconstruction: $2.9 billion

This extensive highway project focused on reconstructing and widening a seven-mile stretch of highway on Interstate 95 (I-95) between New Haven and Branford, Connecticut. By the time the work finished in 2018, it had cost $2.2 billion, which is about $2.9 billion today. 

The program also included building the new 10-lane Pearl Harbor Memorial Bridge over the Quinnipiac River, replacing the existing bridge, which dated back to the 1950s. 

22. Verrazzano-Narrows Bridge: $3.3 billion

At 4,260 feet, the Verrazzano-Narrows Bridge claimed the Golden Gate's crown and became the world's longest suspension bridge when it was completed in 1964. It held on to the title for 17 years before the UK's Humber Bridge usurped it in 1981.

The Verrazzano-Narrows crossing, which connects Brooklyn and Staten Island while spanning New York Harbor, cost $305 million to build, or $3.3 billion when adjusted for inflation.

21. Maryland Route 200: $3.4 billion

Also known as the Intercounty Connector, this 18-mile road project in Maryland was initially proposed back in 1969 but wasn't approved for construction until the early 2000s.

The tolled highway connects I-270 in Gaithersburg, Montgomery County, and US 1 in Laurel, Prince George's County. By the time the work was finished in 2014, it had cost $2.4 billion, or around $3.4 billion today.

=18. I-4 Ultimate: $3.6 billion

The largest highway infrastructure project in Florida's history, the I-4 Ultimate focused on improving a 21-mile-long stretch of Interstate 4 in the Orlando area.

The program included reconstructing 15 interchanges, building 53 new bridges, and replacing or widening another 87 bridges. It also introduced four express toll lanes. Work began in 2015 and finished in 2021, costing $2.9 billion, or $3.6 billion in today's money.

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=18. Crescent Corridor: $3.6 billion

This ambitious project aimed to expand the US freight rail network across 13 states from Louisiana to New Jersey, covering around 2,500 miles.

A public-private partnership between the government and Norfolk Southern Railway, it also included expanding or building terminals in 11 markets, allowing rail freight to compete with the long-haul trucking services offered along nearby interstates and highways.

Cost estimates for the program were $2.5 billion when many of the initial terminals opened in 2012. That's $3.6 billion in today's dollars.

=18. Yankee Stadium: $3.6 billion

The replacement Yankee Stadium in New York cost $2.3 billion to construct in 2009, making it the most expensive stadium ever built at the time.

Controversially, $1.2 billion of public money helped fund the project. Adjusted for inflation, the stadium cost $3.6 billion in today's dollars.

17. Woodrow Wilson Bridge: $3.7 billion

One of the world’s largest drawbridges, the Woodrow Wilson Memorial Bridge (also called the Woodrow Wilson Bridge) carries 12 lanes of traffic over the Potomac River between Alexandria, Virginia and Oxon Hill, Maryland.

Plans for replacing the original bridge, which opened in 1961, had been in motion since the 1980s, although construction didn't begin until 2000. The new bridge opened to traffic in 2008 at a total cost of $2.4 billion, or $3.7 billion today.

=15. Ohio River Bridges Project: $3.9 billion

This complex megaproject included two new bridges, roadways, freeway interchanges, a tunnel, and other facilities that connect Indiana and Kentucky over the Ohio River.

Shared across both states, this new infrastructure was delivered in two programs, with Indiana leading the East End Crossing and Kentucky leading the Downtown Crossing project. Both were completed by 2016 for a grand total of $2.8 billion, equivalent to $3.9 billion today.

=15. Mon/Fayette Expressway: $3.9 billion

Four different road projects made up the Pennsylvania Turnpike Commission’s Mon/Fayette Expressway. Facing funding setbacks, the last part of the program was delayed for several years. Although construction started in 2023 on the first section of the final and largest road, the second section and substantial completion of the entire project are not expected before 2028.

According to 2019 estimates, the Commission has spent $1.9 billion so far, which is $2.5 billion with inflation factored in. The next phase is estimated to cost at least $1.4 billion more.

=13. Alaskan Way Viaduct Replacement Tunnel: $4.3 billion

At 1.7 miles long, this tunnel project was beset by problems from the start of excavation work beneath Seattle in July 2013. Almost immediately after work started, it stalled for two years when the tunnel boring machine, nicknamed "Bertha" and then the largest of its type in the world, needed repairs to its main bearing.

The estimated completion date for the work, which now operates as the State Route 99 tunnel, was shifted from 2015 to 2019. The total cost was $3.3 billion, or $4.3 billion in today's dollars.

=13. Interstate 69 Extension: $4.3 billion

After 16 years of construction, this massive and long-awaited 142-mile extension of Interstate 69 from Evansville to Indianapolis opened to the public in summer 2024. 

The milestone marked completion of construction on the sixth and final section of the overall project, announced in 2008. Work on this last stretch cost $2 billion and began in 2019. It includes 26 miles of interstate, 10 new interchanges, and more than 35 miles of local access roads. The overall program cost $4.3 billion.

12. I-10 Katy Freeway Expansion: $4.4 billion

This wide-ranging expansion of Interstate 10 in Houston was carried out over five years, from 2003 to 2008, costing $2.8 billion at the time, or $4.4 billion today.

Increased traffic in the city meant road congestion lasted for up to 11 hours a day, so a fix was badly needed. Major reconstruction work along a 12-mile section expanded the Katy Freeway to six general lanes in each direction, with two toll lanes.

11. Central Texas Turnpike: $5.1 billion

The Central Texas Turnpike project saw the construction of three toll roads (now known as the Austin Area Toll Roads) in Austin and along the Austin-San Antonio corridor.

They opened to traffic in 2008 after six years of construction and cost around $3.3 billion. That's $5.1 billion when factoring in inflation.

10. One World Trade Center: $5.4 billion

Officially the tallest building in the Western Hemisphere, One World Trade Center is the centerpiece of the rebuilt World Trade Center complex in New York City.

Standing 1,776 feet tall, representing the 1776 signing of the Declaration of Independence, the skyscraper was completed in 2014 at a cost of around $3.8 billion, or $5.4 billion in today's money.

Owned by the Port Authority of New York and New Jersey, the reconstruction has been paid for by a combination of public funding and insurance money.

9. Second Avenue Subway Phase 1: $6.2 billion

Plans for New York’s Second Avenue Subway date back to the 1920s. However, financial roadblocks throughout the 20th century reduced the 8.5-mile project into four phases.

Phase 1, which comprises 1.8 miles of subway line and three stations, opened in 2017 at a cost of $4.5 billion, or $6.2 billion today.

8. Evergreen Point Floating Bridge and HOV program: $6.3 billion

Measuring 7,710 feet, the replacement Evergreen Point Floating Bridge is the longest floating bridge in the world.

Completed in 2016, the six-lane bridge carries State Route 520 across Lake Washington from Seattle to its eastern suburbs. The megaproject also included road widening to add high-occupancy vehicle (HOV) lanes, improved bridge approaches, and other traffic infrastructure improvements.

The total package came to $4.5 billion, or $6.3 billion in today's dollars. 

7. Silver Line Extension: $6.8 billion

This extension to the Silver Line in Washington DC connected the city’s downtown with Dulles International Airport, adding 11 new stations.

Construction took place in two phases, with the final grand opening of the 23-mile line taking place in 2022. The project cost around $6 billion ($6.8 billion in today's money), much of which was funded by drivers on adjacent toll roads.

6. LaGuardia Airport Redevelopment: $9.1 billion

LaGuardia once held the dubious honor of ranking among the worst airports in America, with then-VP Joe Biden comparing it to arriving at "some third-world country" in 2014.

The following year, New York's then-governor Andrew Cuomo launched an ambitious overhaul of the NYC airport, investing billions of dollars into improving its terminals and facilities. 

Private funding covered two-thirds of the cost, and since its completion in 2022, the airport has won awards and acclaim. The total cost was $8 billion, or $9.1 billion in today's money.

5. San Francisco–Oakland Bay Bridge Eastern Span Replacement: $9.3 billion

Replacing a section of the seismically unsound eastern span of the Bay Bridge became one of the most expensive public works projects in California's history, setting the state back an eye-watering $6.5 billion. That's $9.3 billion in today's dollars, significantly higher than the $250 million price tag originally attached to the work back in 1995.

Construction started in 2002 and wasn't completed until 2013.

4. Bay Area Rapid Transit: $10.8 billion

Work on the San Francisco Bay Area Rapid Transit (BART) rail system started in June 1964. With several sections built underground, the project included the construction of the underwater Transbay Tube, a 3.8-mile-long tunnel made up of 57 giant steel and concrete sections immersed beneath San Francisco Bay. 

The first section of the system opened in 1972 and reportedly carried 100,000 passengers across its 28 miles of track in just five days. As of the mid-1970s, it was estimated to have cost $1.6 billion to build, about $10.8 billion in today's money.

3. East Side Access: $13.2 billion

New York’s East Side Access was the Metropolitan Transportation Authority’s (MTA) largest-ever capital project. The work included adding 40 miles of new tracks to the Long Island Rail Road (LIRR) and building a massive new terminal beneath Grand Central.

Construction began in 2001, with 2009 floated as the expected completion date. However, that deadline came and went, and the project finally opened more than a decade later in 2023, costing nearly $12 billion ($13.2 billion with inflation).

2. Central Artery/Tunnel Project: $23.9 billion

The Central Artery/Tunnel Project, nicknamed the "Big Dig," replaced Boston’s tired six-lane elevated Central Artery with a 3.5-mile underground highway. The work also included building two bridges across the Charles River and several new roads.

Needless to say, the project, which launched in 1991, was incredibly expensive and encountered several delays. The final bill topped a staggering $14.8 billion when the project wrapped in 2007, which is $23.9 billion in today's money.

1. Trans-Alaska Pipeline System: $43.4 billion

The Trans-Alaska Pipeline system was built between 1974 and 1977 for $8 billion, making it the world's largest privately funded project at the time. In today's dollars, that's around $43.4 billion.

Crucial to the Alaskan economy, the 800-mile-long pipeline has been instrumental in facilitating the growth of the state's oil industry.

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