One of the most frustrating aspects of Atlanta traffic is how much I-285 affects so many other roads. Wrecks and construction on I-285 jam up intersecting interstates, but the bigger sin of I-285 is just trying to hook up with it. Pardon the entendre.
An annoying aspect of everyday rush hour is the right-lane jam that occurs when certain freeway traffic lines up to ramp onto I-285. This has become even more of a problem as more freight traffic clogs Georgia’s roads with the deepening of the Port of Savannah. And most of those commercial rigs have to bypass downtown Atlanta — via Atlanta’s bypass, of course. Another thing making I-285 merging worse is just the sheer increase in population not just in the City of Atlanta, but in all of the satellite cities in the suburbs. There are many more jobs in an array of places all over metro Atlanta, meaning there are many more rush hour directions for traffic flow.
For example, both I-75/southbound in Cobb and I-85/southbound in DeKalb are usually slow in PM drive, as they ramp to I-285. This is going against the normal outbound PM drive flow. And when the ramps aren’t slow, they take no time getting that way when problems happen near I-285 or on the Perimeter.
But the delays pop up outside of rush hour and at random times. On Wednesday mid-morning — well before the roads really got into the bad Thanksgiving travel mode — the I-75/southbound right lanes were already slow below Delk Road down to I-285. It was just volume. In fact, more than half of the interstate volume seemed to be exiting onto the Perimeter.
So that got me down a traffic wormhole. Why do interchanges have such little real estate dedicated to feeding onto other freeways? The traffic volume seems to demand more capacity. And I-285 interchanges seem to be the most lacking.
Spaghetti Junction (the I-85/I-285 interchange in DeKalb) generally gets the most flack. One measure of its jam is the American Transportation Research Institute’s study of trucking bottlenecks. ATRI ranked Spaghetti Junction as causing the worst freight gridlock of any interchange in the nation in both 2017 and 2018. This increasing gridlock, of course, adds costs to the companies that operate the trucks and the buyers of those products. And the Spaghetti Junction ramps aren’t just slow during rush hour. As noted above, the non-rush hour directions get backed up and a small crash on a weekend or midday weekday can snarl one of those ramps easily.
I-75 at I-285 in Cobb, the Cobb Cloverleaf, was ninth in the 2017 ATRI study and up (or down) to fifth in 2018. It may have gotten worse because of the three-plus-year I-75 Peach Pass Lanes project. However, those new lanes do give some added capacity in that interchange and improve the overall traffic on I-75. But they only run in one direction, so if traffic queues up in the other way, it doesn’t have the benefit of the lanes.
As part of GDOT and the Atlanta Regional Commission’s extensive 10-year traffic plan, rebuilds of both the I-20 at I-285 interchange in Fulton (17th-worst on ATRI’s 2018 list) and Spaghetti Junction are on the drawing board. The Spaghetti Junction rebuild really simply involves more ramps and an integration into future toll lanes that GDOT will build along I-285. They also want to make a HOT lane-only set of ramps to I-285, similar to what exists on the new toll system in Cobb and with the HOV system on I-75’s Brookwood merge with the Downtown Connector.
The I-20 at I-285 rebuild in Fulton County is even more urgent. There is no “spaghetti” in that junction. It’s more like a couple of breadsticks and some Spaghetti O’s. That interchange has only one lane in any direction to make the transition. It is the worst in PM drive, when I-285 is stacked both ways trying to ramp onto I-20/westbound. A search of the GDOT projects site shows that widening is part of this interchange rebuild. That certainly will mean better-moving ramps and more lanes to push through the increasing traffic volume. But this may be years away.
I-285 is either the most or second-most important metro Atlanta interstate and improving it is always a moving target. Funding for new projects comes from the same pie that has to repave it every few years — and cut the grass, and replace signs, and rehab bridges. The Transform I-285/GA-400 project is still in its early stages, but will be the first measure after the Peach Pass lanes in Cobb to make interacting with I-285 better. But there is no doubt that the future projects just detailed will also make a dent in this problem. But as things stand today, hooking up with I-285 needs to be much smoother and easier.
Doug Turnbull, the PM drive Skycopter anchor for Triple Team Traffic on News 95-5 FM and AM-750 WSB, is the Gridlock Guy. He also writes a traffic blog and hosts a podcast with Smilin’ Mark McKay on wsbradio.com. Contact him at Doug.Turnbull@coxinc.com.