Can a Tunnel Cure Atlanta's Congestion?

This article from Reason argues that a double-decker traffic tunnel can effectively reduce congestion in Atlanta -- one of the most congested cities in America.

2 minute read

June 4, 2008, 7:00 AM PDT

By Nate Berg


"In April, Forbes ranked the metro-Atlanta region the second most congested city in America. It has been estimated that the direct cost of that congestion to Georgia motorists is $1.75 billion per year. Fear not my fellow weary travelers, there are solutions out there that, by thinking outside the box, can address this looming crisis."

"On a recent trip to the metro area, I learned that Cobb County has broken ground on a 24-foot diameter wastewater tunnel that will be 29,100 feet (5.5 miles) long. This sewer tunnel will run from just south of Austell to the South Cobb Water Reclamation Facility just north of I-20. I was already aware of the Chattahoochee Tunnel that is 18 feet in diameter and 9.5 miles long, and it got me thinking about tunnels and creative solutions to the congestion crisis that Atlanta faces day in and day out."

"What if I were to tell you that there is a way to provide the needed capacity in the most congested area, the Downtown Connector, while protecting Atlanta's neighborhoods? Well, my colleague, Robert Poole has proposed building a double-decked road tunnel, (similar to the new sewer tunnel that is currently underway in Cobb County), which would link the southern terminus of Georgia 400 with I-20 and later with the northern terminus of I-675. This tunnel is only one of perhaps half a dozen major projects needed relieve metro Atlanta's congestion but would provide the most dramatic relief. This proposed tunnel would have an inside diameter or 45 feet and each deck would have three 11 foot lanes and an overhead clearance of 12 feet allowing the tunnel to accommodate buses as well as SUVs and cars. The northern tunnel would be 5 miles long and the southern one would be 3.1 miles in length."

Tuesday, May 27, 2008 in Reason

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Use Code 25for25 at checkout for 25% off an annual plan!

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

May 7, 2025 - Diana Ionescu

People biking along beach path with moored ship in San Diego, California.

San Diego Adopts First Mobility Master Plan

The plan provides a comprehensive framework for making San Diego’s transportation network more multimodal, accessible, and sustainable.

May 2, 2025 - SD News

Front of Walmart store with sign.

Walmart Announces Nationwide EV Charging Network

The company plans to install electric car chargers at most of its stores by 2030.

May 7, 2025 - Inc.

Pump station with blue pipes coming out of concrete wall in Seattle, Washington.

Seattle Builds Subway-Sized Tunnel — for Stormwater

The $700 million ‘stormwater subway’ is designed to handle overflows during storms, which contain toxic runoff from roadways and vehicles.

3 hours ago - City Observatory

Sign for Deschutes National Forest in Oregon.

Feds Clear Homeless Encampment in Oregon Forest

The action displaced over 100 people living on national forest land near Bend, Oregon.

5 hours ago - The New York Times

Seeing the Better City

Is This Urbanism?

Chuck Wolfe ponders a recommended subscription list of Substack urbanists and wonders — as have others — about the utility of the "urbanist" moniker.

6 hours ago - Resurgence: A Journey via Substack

Urban Design for Planners 1: Software Tools

This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.

Planning for Universal Design

Learn the tools for implementing Universal Design in planning regulations.