10 Abandoned Transportation Projects That Could Have Changed the Nation

Throughout U.S. history, grand transportation projects have been proposed to reshape the country’s mobility and economy. Some of these projects aimed to revolutionize urban transit, connect remote regions, or modernize infrastructure on a massive scale. However, not all of them came to fruition. These abandoned plans, often halted by funding issues, politics, or public opposition, leave us wondering how the U.S. might look today if they had succeeded.

Here are ten ambitious transportation projects that were abandoned and could have dramatically altered the nation’s landscape.

Related: 10 Crazy Encounters of UFOs, Speeding Trains, and the Railroads

10 Cincinnati’s Abandoned Subway

In the early 20th century, Cincinnati began constructing a subway system to modernize its public transit and alleviate streetcar congestion. Construction began in 1920, and by 1925, nearly seven miles of tunnels and multiple stations were almost complete. The tunnels were designed to accommodate streetcars and future electric trains, with engineers envisioning an interconnected transit network rivaling larger cities. However, the project ran out of funding due to inflation following World War I, and subsequent efforts to restart construction were thwarted by the Great Depression and political resistance. Plans to repurpose the tunnels for freight or highway use also fell through, leaving the project abandoned.

Today, the unused subway tunnels remain beneath Cincinnati’s streets, a haunting reminder of what might have been. Occasionally opened for tours, the tunnels are structurally sound but serve no practical purpose. Modern attempts to establish a rail system in Cincinnati have struggled, leaving the city with limited transit options compared to its peers. The subway’s failure not only stunted Cincinnati’s development but also shifted its trajectory toward car-centric infrastructure, missing an opportunity to create a transit-driven urban core.^[1]

9 The Interstate 710 Extension in Los Angeles

Interstate 710, known as the Long Beach Freeway, was envisioned as a major north-south artery connecting the ports of Long Beach to the 210 Freeway in Pasadena. Proposed in the 1950s, the extension was meant to ease traffic congestion and provide a direct route for freight transport. However, the project faced fierce opposition from communities along the proposed route.

Residents in South Pasadena, a historic neighborhood, argued that the freeway would destroy homes, increase pollution, and disrupt local businesses. Lawsuits, protests, and environmental reviews delayed the project for decades. By the 1990s, political resistance and public outcry had effectively stalled the extension indefinitely.

The absence of the extension has left a glaring gap in Southern California’s highway system. Drivers are forced to navigate congested surface streets, increasing traffic in residential areas. Although preserving South Pasadena’s character has been celebrated, the trade-off has been decades of inefficiency in a region already notorious for gridlock. Proposed alternatives, such as underground tunnels or light rail, have yet to gain traction, leaving the 710 Extension one of L.A.’s most contentious transportation failures.^[2]

8 New York City’s Second Avenue Subway (Original Plan)

The Second Avenue Subway was first proposed in the 1920s as a solution to overcrowding on the Lexington Avenue Line, the only subway serving Manhattan’s East Side. The original plan envisioned a full-length line stretching from Harlem to Lower Manhattan, connecting underserved neighborhoods and creating a much-needed north-south transit route. Construction was sporadic, with brief progress in the 1970s before funding dried up again.

Decades of political gridlock, economic downturns, and shifting priorities left the project in limbo. Although a truncated version of the line finally opened in 2017, it only includes three stations and covers a fraction of the original vision. Had the full line been completed as planned, it could have transformed transit on Manhattan’s East Side, easing congestion and reducing reliance on buses.

The delays not only left millions of commuters underserved for decades but also increased construction costs exponentially. The project’s piecemeal implementation remains emblematic of the challenges facing major infrastructure projects in the U.S., with the unfinished sections serving as a reminder of missed opportunities.^[3]

7 Boston’s Elevated Highways Replacement Plan

In the 1960s, urban planners in Boston proposed a radical idea to demolish the city’s elevated highways entirely. Instead of expanding roadways, they suggested reallocating federal funds to public transit projects to reduce car dependency and reconnect neighborhoods divided by highways. This proposal, known as the “Highway Moratorium,” gained traction as public opposition to urban freeways grew. The plan envisioned a Boston where subways and light rail systems dominated, leaving more space for parks, pedestrians, and businesses.

The moratorium never fully materialized, and Boston instead pursued the Big Dig decades later, relocating highways underground. While the Big Dig successfully addressed some congestion and restored parts of the city’s character, prioritizing transit in the 1960s could have reshaped Boston as a leader in sustainable urban development. The decision to preserve some highways instead of fully committing to transit left Boston with a compromise rather than a bold solution to its transportation challenges.^[4]

6 The Florida High-Speed Rail Project

Florida voters approved a constitutional amendment in 2000 to construct a high-speed rail network connecting major cities like Tampa, Orlando, and Miami. Advocates envisioned a system that would reduce reliance on cars, cut travel times, and provide an environmentally friendly alternative to flying. Initial plans included modern rail stations and trains capable of traveling 125 miles per hour (201 km/h).

Construction began in the early 2000s, but the project faced significant political opposition. Governor Jeb Bush repealed the amendment in 2004, arguing that the costs outweighed the benefits. A revived version in 2011 was also canceled after Governor Rick Scott rejected federal funding.

The cancellation left Florida dependent on its congested highway system and fragmented transit options. If completed, the rail network could have addressed the state’s growing transportation needs and served as a model for other regions. Private companies like Brightline have since tried to fill the gap with limited high-speed rail services. Still, these efforts pale in comparison to the original statewide vision.^[5]

5 Chicago’s Airport Supertrain

In the 1990s, Chicago proposed building a high-speed rail system to connect O’Hare International Airport, Midway Airport, and downtown Chicago. The supertrain was designed to reduce highway congestion and improve passenger travel times, providing a seamless link between the city’s major transportation hubs. Planners envisioned sleek stations integrated into the airports, making Chicago a model of interconnected transit. However, the project faced numerous hurdles, including cost overruns, political disagreements, and questions about whether passenger demand justified the investment. By the early 2000s, the plan was shelved.

Without the supertrain, travelers in Chicago rely heavily on taxis, rideshares, and highways to move between airports, exacerbating congestion and travel delays [LINK 6]. If implemented, the project could have enhanced Chicago’s reputation as a global transportation hub, setting a standard for other cities. Instead, the lack of coordination between air and ground transit remains a glaring inefficiency in an otherwise vibrant metropolis.^[6]

4 Baltimore’s Red Line

The Baltimore Red Line was a proposed 14-mile east-west light rail line designed to connect the city’s underserved neighborhoods with job centers and existing transit networks. Approved in 2002, the project secured federal funding and promised to address Baltimore’s transportation inequities. The Red Line was also seen as a way to revitalize struggling areas, offering faster commutes and increased economic opportunities. However, in 2015, Governor Larry Hogan canceled the project, reallocating its $900 million in federal funding to highway improvements in rural areas.

The cancellation left Baltimore with one of the weakest transit systems among major U.S. cities, further isolating low-income communities. Critics argue that abandoning the Red Line perpetuated systemic inequality, missing an opportunity to boost mobility and economic development. The decision remains a flashpoint in Maryland politics, with advocates continuing to push for a revival of the plan.^[7]

3 The Pacific Electric Railway Expansion

The Pacific Electric Railway once boasted over 1,000 miles (1,609 km) of track, connecting Los Angeles to surrounding cities and suburbs in the early 20th century. At its peak, it was the largest interurban railway system in the world. Expansion plans in the 1920s aimed to further integrate Southern California’s transit network, but the rise of automobile culture and aggressive lobbying by car manufacturers led to the gradual dismantling of the system. By the 1960s, nearly all of the rail lines had been replaced by freeways and buses.

The loss of the Pacific Electric Railway left Los Angeles car-dependent, with notorious traffic problems and sprawling development patterns. If the expansion had succeeded, the region could have maintained a robust public transit network, reducing environmental impacts and creating a more sustainable urban landscape. The dismantling of the railway is now viewed as a cautionary tale of shortsighted planning.^[8]

2 Texas’s Trans-Texas Corridor

Proposed in the early 2000s, the Trans-Texas Corridor was envisioned as a massive network of superhighways, freight rail, and pipelines spanning the state. Planners aimed to create a seamless infrastructure system to accommodate Texas’s rapid population growth and improve North American trade. The corridor would have included toll roads, high-speed rail, and truck-dedicated lanes, promising faster travel times and increased economic efficiency. However, the project faced intense opposition from landowners, environmentalists, and local communities, who argued it was too costly and would displace thousands of residents.

The project was officially canceled in 2010, leaving Texas grappling with its transportation challenges. As the state’s population continues to grow, congestion and infrastructure strain have worsened. Had the corridor been built, Texas might have become a model for integrating multiple modes of transportation into a single cohesive system.^[9]

1 The Alaska-Canada Rail Link

First proposed in the 1950s, the Alaska-Canada Rail Link aimed to connect Alaska’s rail network to the rest of North America through Canada. Renewed discussions in the early 2000s envisioned a route to facilitate trade, tourism, and resource extraction, providing economic benefits to remote regions. However, the project faced immense challenges, including its estimated $20 billion cost and the logistical difficulty of building across rugged terrain and permafrost. Political complications between the U.S. and Canada also hindered progress.

Without the rail link, Alaska remains largely isolated, relying on limited roadways and shipping routes to connect with the lower 48 states. If completed, the project could have unlocked vast economic opportunities, creating a vital transportation corridor for North American trade. Its abandonment highlights the difficulties of executing ambitious infrastructure projects in remote areas.^[10]