How to ‘stitch’ up downtown’s traffic problems

If for some sadistic reason you wanted to make driving through Atlanta even more miserable, a very good option would be “blot out the sun.”

That’s exactly what would happen if part of the Downtown Connector is covered up by a 14-acre deck topped with parks, new road connections and even more buildings. Commuters and passers-through would not only lament the traffic they were enduring, but know there was something approximating joy going on overhead.

I may be painting this idea — dubbed “The Stitch” because it would mend the ties between Midtown and downtown — too darkly. The rending of intown neighborhoods by I-75/85 years ago has long had ill effects, and correcting those is worthwhile (depending on the price, which started at $300 million and, as with all such projects, will surely go up).

But I frame it in terms of drivers for a reason. Whatever the dreams one might have for the space above the Connector, the fact remains we are talking about a dozen or so lanes of interstate that, for many hours of the day, are jam-packed. With the region’s population only expected to continue growing by millions in the decades to come, that problem isn’t going away.

One idea for traffic relief is to build more lanes above the Connector. Most likely, that won’t happen. But anyone who would foreclose that possibility by building something else above the interstates should propose an alternative way to move more people through the city. Streetcars don’t count.

Happily, I have an idea they can steal. It still involves hoisting lanes into the sky, just not above the Connector.

What I mean is a western bypass of downtown built above U.S. 41: from just before the Brookwood Interchange where I-75 merges with I-85 on the north side, all the way down to where the interstates diverge again near Cleveland Avenue.

Two lanes in each direction, built above a mostly commercial and industrial area and leaving existing east-west streets undisturbed. Very few exits, to prevent adding traffic to the area below and reserve the new expressway as a true downtown bypass. A measure of roadway redundancy in a region that doesn’t have much of that, as commuters are painfully aware each time a wreck shuts down all or most of a major artery.

Based on the cost per lane-mile of the managed lanes being built on 75 and 575, much of which are also elevated, this 10-mile road might be built for less than $900 million. Not bad, compared with that $300 million for covering three-quarters of a mile over the Connector.

Such a project would add much-needed north-south capacity through town. It would also allow for a great deal of flexibility in shaping transportation policy.

The corridor could be a preferred roadway for autonomous vehicles as they come online, separating them from most other vehicles passing through town. It could offer an additional route for transit vehicles connecting the northern suburbs with the airport.

And because the Connector will eventually need toll lanes to complete the region’s growing network of managed lanes, a western bypass would also allow the state to add them without reducing the number of “free” lanes available.

Atlanta is often drawn to big ideas like “The Stitch.” The problems such ideas create deserve big solutions of their own.