I-75/I-285 NW Cobb Cloverleaf freeway interchange (Atlanta: transportation, design)

[Born 2 Roll]

A few days ago, the Atlanta Journal-Constitution posted a page very briefly highlighting the “Cobb Cloverleaf” interchange.

The relatively short AJC page seemed to be aimed at attempting to educate unknowing metro Atlanta newcomers to the local nickname of the Interstate 75/285 interchange near major local points-of-interest of regional importance (including Truist Park, The Battery and Cumberland Mall) in the Cumberland area of Northwest metro Atlanta in Cobb County.

Where is the Cobb Cloverleaf in Atlanta? I-75 at I-285 (Atlanta Journal-Constitution)

[Born 2 Roll]

Originally Posted by Born 2 Roll

A few days ago, the Atlanta Journal-Constitution posted a page very briefly highlighting the “Cobb Cloverleaf” interchange.

The relatively short AJC page seemed to be aimed at attempting to educate unknowing metro Atlanta newcomers to the local nickname of the Interstate 75/285 interchange near major local points-of-interest of regional importance (including Truist Park, The Battery and Cumberland Mall) in the Cumberland area of Northwest metro Atlanta in Cobb County.

Where is the Cobb Cloverleaf in Atlanta? I-75 at I-285 (Atlanta Journal-Constitution)

One thing that probably may be little known about the I-75/I-285 Cobb Cloverleaf is that the official name of the interchange is the Emory C. Parrish Interchange.

Emory C. Parrish was a deputy commissioner for the Georgia Department of Transportation who helped to start and lead the planning of the I-285 Perimeter back in the 1950’s.

The Cobb Cloverleaf nickname of the busy freeway interchange dates back to when the I-75/I-285 Northwest interchange still had its original cloverleaf freeway interchange design.

[Citykid3785]

Now If we could just get rid of semis, it would be a pleasant interchange!

Kidding of course, I recognize the importance of semis

[Need4Camaro]

Cobb Cloverleaf along with Spaghetti Junction were originally built as cloverleafs with the flyovers added and surface ramps modified later right?

One thing I do like about the Cobb Cloverleaf is you have two options to take I-285 EB (heading toward Perimeter) from I-75 SB (heading toward Atlanta). The Flyover ramp that exits right after Windy Hill, and the loop around ramp that exits right after the I-285 overpasses. I have admittedly found that redundancy to come in handy on the occurrence that the flyover ramps are packed and noone bothers to go a quarter mile farther to the loop around ramp...

[Born 2 Roll]

Originally Posted by Need4Camaro

Cobb Cloverleaf along with Spaghetti Junction were originally built as cloverleafs with the flyovers added and surface ramps modified later right?

Spaghetti Junction (the I-85/I-285 Northeast interchange) was originally built as a full cloverleaf interchange in the late 1950’s/early 1960’s.

The Cobb Cloverleaf was originally built in the late 1960’s as a combination partial cloverleaf/directional interchange with the two existing loop ramps (from I-75 SB to I-285 EB, and from I-75 NB to I-285 WB) and two left lane exit directional ramps (from the left lane of I-285 WB to I-75 SB, and from the left lane of I-285 EB to I-75 NB).

Originally Posted by Need4Camaro

One thing I do like about the Cobb Cloverleaf is you have two options to take I-285 EB (heading toward Perimeter) from I-75 SB (heading toward Atlanta). The Flyover ramp that exits right after Windy Hill, and the loop around ramp that exits right after the I-285 overpasses. I have admittedly found that redundancy to come in handy on the occurrence that the flyover ramps are packed and noone bothers to go a quarter mile farther to the loop around ramp...

The reason for the redundancy of those ramps from I-75 SB to I-285 EB (both the flyover ramp and the loop ramp) is because there’s no access from Windy Hill Road to the flyover ramp from I-75 SB to I-285 EB. So they left the original loop ramp design from I-75 SB to I-285 EB so that traffic from Windy Hill Road would be able to access I-285 EB.

[Need4Camaro]

On a side note, I think I read somewhere that this interchange is the busiest freeway junctions in the entire Southeastern Region. It may be plausible given the amount of truck traffic that has to utilize I-75 and also I-285.

Are they still going to extend the HOT lane further south of that interchange toward Cumberland Blvd?

[Mossberg]

Originally Posted by Need4Camaro

On a side note, I think I read somewhere that this interchange is the busiest freeway junctions in the entire Southeastern Region. It may be plausible given the amount of truck traffic that has to utilize I-75 and also I-285.

Are they still going to extend the HOT lane further south of that interchange toward Cumberland Blvd?

Yes, they are still going to build the additional HOT lane exits.

[waronxmas]

The auto censor in this forum won't allow me to post my name for that interchange...

[Born 2 Roll]

Originally Posted by Need4Camaro

On a side note, I think I read somewhere that this interchange is the busiest freeway junctions in the entire Southeastern Region. It may be plausible given the amount of truck traffic that has to utilize I-75 and also I-285.

You raise an excellent point, which is that the I-75/I-285 Cobb Cloverleaf interchange has been rated as one of the worst freight truck bottlenecks in not just the Southeast, but the entire U.S.

Here are some links from 2017 that rated the Cobb Cloverleaf interchange as the 9th-most congested freight truck bottleneck in the entire U.S.

Interestingly, it was the I-85/I-285 ‘Spaghetti Junction’ interchange in Northeast metro Atlanta that ranked as the most congested freight truck bottleneck in the entire nation.

The I-20/I-285 West interchange was ranked in the Top-15 of the list at #14.

The I-20/I-285 East interchange ranked #43 on the list.

The I-20 at I-75/I-85 interchange south of Downtown Atlanta ranked at #62 on the list.

I-75 at I-675 in Henry County in South metro Atlanta ranked at #66 on the list.

“I-75 at I-85” (presumably at the delay-prone Brookwood Interchange in Midtown Atlanta) ranked #73 on the list.

Top 10 truck freight bottlenecks: ATRI lists U.S.’ most congested highway interchanges (Overdrive)

2017 Top 100 Truck Bottleneck List (ATRI/American Transported Research Institute)