Could Atlanta Ever Build a True Underground Subway?

Atlanta traffic is legendary, MARTA rail doesn’t reach everywhere, and many residents and visitors wonder: is it actually possible to build an underground subway in Atlanta?

The short answer: yes, it is technically possible to build more underground subway lines in Atlanta—but it would be extremely complex, slow, and expensive, and would depend heavily on local politics, funding, and public support.

This guide walks through what “possible” really means in Atlanta, how MARTA’s existing system fits in, what challenges an underground subway would face here, and what it would mean for people trying to get around the city.

What Atlanta Already Has: Is MARTA a Subway?

Before talking about a new underground subway, it helps to understand what already exists.

MARTA’s heavy rail system (the Red, Gold, Blue, and Green lines) is a mix of:

• Underground segments – especially downtown and Midtown, including stations like:
  • Peachtree Center
  • Five Points
  • Civic Center
• Elevated tracks – in many parts of the city and suburbs
• At-grade (surface) sections

So technically, Atlanta already has subway-style underground rail, but:

• It is limited mostly to the core (Downtown, Midtown, part of Buckhead).
• It does not form a dense underground network like New York City or London.
• Many major destinations (like parts of the BeltLine, westside neighborhoods, and many suburbs) don’t have rail at all, or are only served by buses.

When people ask, “Can Atlanta build an underground subway?” they usually mean:

• More lines
• More coverage across the metro
• A system that lets you get around without a car in many parts of the city

That is a bigger question than just digging tunnels—but underground construction is a central part of it.

Is It Technically Possible to Build an Underground Subway in Atlanta?

From an engineering point of view, yes, it’s possible. Atlanta does not have any single natural feature that makes subway tunnels impossible.

Engineers look at things like:

• Geology and soil conditions
• Existing utilities (water, sewer, power, fiber)
• Existing building foundations
• Groundwater levels and nearby streams

Atlanta’s Ground Conditions

Much of the Atlanta area sits on the Piedmont—a region with:

• Granite and hard rock in many places
• Clay and mixed soils elsewhere
• Rolling hills rather than flat terrain

This mix doesn’t prevent tunneling, but it affects:

• Construction methods (boring machines vs. cut-and-cover)
• Cost (harder rock can be more expensive to dig through)
• Timeline and disruption

Atlanta’s existing MARTA tunnels (especially downtown) prove that tunnels can be safely and successfully built under busy streets and dense development.

What Are the Biggest Challenges?

The main obstacles to expanding an underground subway in Atlanta are not technical—they’re practical and political.

1. Cost

Building underground rail is usually one of the most expensive types of infrastructure a city can undertake.

Costs include:

• Designing routes and stations
• Excavating tunnels and shafts
• Moving or protecting underground utilities
• Building ventilation, emergency exits, and safety systems
• Buying and running trains and maintenance facilities

Because of this, Atlanta would likely need:

• New taxes or fees (often via ballot measures)
• Long-term funding commitments from local governments
• Possible state or federal support

2. Political Will and Regional Cooperation

The Atlanta metro crosses many cities and counties, including:

• City of Atlanta
• Fulton, DeKalb, Clayton, Gwinnett, Cobb, and others

To build a major underground subway expansion, regional leaders and voters would need to agree on:

• Where new lines go
• Who pays what share
• How decisions are made over decades

In the past, some counties have been hesitant to join or expand MARTA participation, which has slowed regional rail growth.

3. Land Use and Density

Subways make the most sense where:

• A lot of people live or work within walking distance
• There are major job centers or high-demand corridors
• There is limited road capacity or heavy congestion

Parts of Atlanta (like Midtown, Downtown, Buckhead, and parts of the BeltLine area) are dense enough that subway-style transit could be justified. But many areas in the region are lower-density, where:

• Bus rapid transit
• Light rail or streetcar
• Or better bus service

might be more practical than a full underground subway.

How Would an Underground Subway Even Work Here?

If Atlanta decided to pursue more underground subway segments, several patterns are likely:

Possible Corridors (Conceptually)

While no citywide underground system is officially planned right now, discussions in Atlanta often center on corridors like:

• Downtown–Midtown–Buckhead spine
• Connections to Atlanta BeltLine segments
• Strong links to Hartsfield-Jackson Atlanta International Airport (MARTA already has a direct rail link, but future capacity or extensions could be considered)
• High-demand east–west or north–south corridors where road widening is limited

Any real project would involve years of public input, studies, and environmental review before routes are chosen.

Types of Construction

Common methods include:

• Bored tunnels

  • Deep tunnels drilled by a tunnel-boring machine
  • Less surface disruption, but usually more expensive

• Cut-and-cover

  • Digging a trench from the surface, building the tunnel, then covering it
  • More disruptive to streets and businesses during construction
  • Sometimes cheaper in the right conditions

Which method is used in Atlanta depends on depth, street layout, utilities, and nearby buildings.

What Role Does MARTA Play?

Any underground subway expansion in Atlanta would almost certainly involve MARTA (Metropolitan Atlanta Rapid Transit Authority), which manages:

• Heavy rail subway-style trains
• MARTA bus network
• Some paratransit services

For residents and visitors, MARTA is the main point of contact for rail transit planning.

MARTA Headquarters (for reference):
MARTA Headquarters Building
2424 Piedmont Road NE
Atlanta, GA 30324
Main Phone: 404-848-5000

You can contact MARTA or follow their public meetings to:

• Learn about current expansion projects
• Track long-range transit plans
• Share input when they ask for public comments

Current Reality vs. Future Possibility

To understand what’s realistic, it helps to compare today’s system with what a future underground subway might look like.

Atlanta Transit: Today vs. Hypothetical Future

For most people living in or visiting Atlanta, the impact would show up as:

• More rail stations within walking distance of homes and offices
• Shorter trips between popular destinations
• Less pressure on highways and surface streets—over time, not overnight

How Would This Affect Visitors and Residents Getting Around?

If you’re wondering about a future underground subway because you’re thinking about how to navigate Atlanta, here’s what matters now and what might matter later.

For Visitors

Right now:

• You can ride MARTA directly from the Airport Station into Downtown or Midtown.
• Most hotels in Downtown and Midtown are within walking distance of a MARTA rail station.
• For neighborhoods without rail (like some parts of the BeltLine, West Midtown, or certain suburbs), you’ll likely rely on:
  • Ride-hail services
  • Taxis
  • Buses
  • Rental cars

In a future with more underground subway lines, visitors might:

• Arrive at the airport and transfer more easily to multiple lines underground
• Take rail to more neighborhoods, events, and attractions without a car

For Residents

Today, your options depend heavily on where you live and work:

• If you’re near an existing MARTA station (e.g., near North Avenue, Arts Center, Lindbergh Center, or King Memorial), rail can already be your daily commute.
• If you’re in car-dependent parts of the metro, your daily travel is probably still built around driving.

A future underground subway could:

• Make non-driving lifestyles more practical in more parts of the city
• Support denser, walkable neighborhoods around new stations
• Reduce commute times along congested corridors

But these changes would unfold slowly, over many years or decades.

What’s Being Discussed Now Instead of a Huge Underground Subway?

While a full-blown, citywide underground subway network isn’t underway, Atlanta and the broader region are exploring and pursuing other transit improvements, such as:

• MARTA infill stations and extensions
• Bus Rapid Transit (BRT) in key corridors
• Streetcar or light rail concepts around the Atlanta BeltLine and other areas
• Better regional coordination through agencies like the Atlanta-Region Transit Link Authority (ATL)

Many of these projects are designed to:

• Improve mobility and reliability
• Add options beyond driving
• Do so at a lower cost than deep-subway systems

If future conditions, funding, and public support line up, some of these corridors could theoretically evolve into partially or fully underground segments in the long term.

How Can You Stay Informed or Get Involved?

If you live in Atlanta or plan to keep returning here, you can track or influence how underground transit evolves by:

• Following MARTA public meetings and long-range planning updates
• Participating in City of Atlanta or Atlanta Regional Commission planning processes when they ask for feedback
• Watching local ballot measures or funding proposals for transit expansion

Key public agencies involved in long-term transit and transportation planning include:

• Metropolitan Atlanta Rapid Transit Authority (MARTA)
  2424 Piedmont Road NE, Atlanta, GA 30324
  Phone: 404-848-5000

• Atlanta Regional Commission (ARC)
  229 Peachtree Street NE, Suite 100, Atlanta, GA 30303
  Main Phone: 404-463-3100

These organizations don’t just handle current services—they also help guide the big-picture decisions about how people will get around Atlanta decades from now.

So, Is an Underground Subway in Atlanta Possible?

From an engineering standpoint, yes—Atlanta can build more underground subway infrastructure, and it already has some in place through MARTA’s existing tunnels.

From a practical standpoint, actually seeing a large new underground subway network would require:

• Major, long-term funding
• Regional political alignment
• Sustained public support
• Careful planning focused on high-demand, dense corridors

For now, if you’re living in or visiting Atlanta, it’s useful to think of the city as having:

• A core heavy-rail system (partly underground) that’s essential for travel between the Airport, Downtown, Midtown, and some key suburbs
• A growing menu of surface transit options (bus, BRT, possible light rail) that may expand coverage faster than deep subways

The idea of a broader underground subway in Atlanta remains possible, but long-term and uncertain. What is certain is that public input, local choices, and steady investment will determine how far the city moves in that direction.