The Four Lane had, not four lanes in each direction, but two. I-75, on the other hand, has five and six and seven and probably even more lanes than that going in each direction in some of its stretches through Cobb. And it’s still crowded!
I-75 has been widened and widened and widened since its construction through Cobb in the 1970s, and needs to be widened again. Only there’s really no room to widen it any further. Land costs would be astronomical.
The latest proposal for dealing with the congestion involves adding reversible lanes that would run on the west side of the interstate in some places and down the median in others.
It’s a reversible-lane concept put forth by the state Department of Transportation, and as shared with Marietta Rotary Club members on Wednesday by DOT highway engineer Darryl D. VanMeter.
Georgia has reversible lanes on Highway 9 (Roswell Road) heading south from downtown Roswell to the Chattahoochee River Bridge, and they’ve worked satisfactorily for the past few decades. But there are none in Cobb County. They’ve been talked up at times for the crowded Whitlock Avenue corridor. But nothing ever happens regarding Whitlock, except talk, talk and more talk. But if it turns out that they are a solution for I-75, maybe someday we can give them a try on Whitlock.
VanMeter said the managed-lane concept is a recognition that “we can’t build ourselves out of congestion. In order to add enough lanes to the interstate, we would have to add so much laneage it would be cost prohibitive.”
How much would that be? Try about $4 billion, VanMeter said.
So the proposed $960 million cost for the reversible lanes wins by comparison.
“Compared to $4 billion, that’s pretty good,” he told the club.
But managed lanes do result in added mobility, he said.
“Managed lanes allow us to preserve the mobility in that lane and be able to sustain that mobility, and the tool that you use in that concept is pricing,” he said.
As he explained it, airlines use the concept. Think about flights to Hawaii. If the price for a ticket to get there was just $5, the airlines could never add enough capacity to handle the demand. Instead, the price goes up to a point where there is sufficient infrastructure, or in this case, enough planes, to handle the demand, VanMeter explained.
And the Northwest Corridor Reversible Lane concept would have mechanisms in place to help preserve those new lanes’ mobility, unlike is the case for the general-purpose lanes.
The new lanes would be designed to keep traffic moving at or near 45 mph, he said. Incidentally, the managed, reversible lanes would be completely closed during non-peak hours, he said.
They are part of a statewide strategic transportation objective, he said.
“This project is not just a small fix,” he said. “It is part of a big step forward toward a network of managed lanes in the metro area.”
Similar managed-lane systems are already employed in Houston, Los Angeles and Seattle, to name just a few, VanMeter said.
The reversible lanes would stretch for 29.5 miles, starting at the I-75 intersection with I-285 at the Galleria, he said. They would stretch north the Hickory Grove exit on I-75 and northward to Sixes Road on I-575.
“That’s why we call it the ‘Northwest Corridor’ concept,” he said. “It’s not just one interstate or the other.
And it will not involve just managed lanes (like HOT and HOV lanes), but reversible lanes.
“They will be barrier-separated from the other lanes, so you’re not going to have the option of accidentally getting onto the lanes at the wrong time going in the wrong direction. Access will be prohibited from the wrong direction,” he said.
At the south end, the reversible lanes will connect with I-285. Northbound vehicles on I-75 would connect with the new lanes via a flyover ramp south of the Windy Hill interchange, he said. An elevated section of the managed lanes would carry traffic over Windy Hill, leaving traffic on that already-busy road uninterrupted, he said.
Those traveling on I-285 will be able access the new lanes going north, too. There’s also a good chance that southbound travelers on the managed lanes might have the opportunity to funnel off onto similar managed lanes heading east and west on I-285, and without having to enter the general-purpose lanes to do so, he said.
Disruptions due to construction will hopefully be minimal because most of the work will take place on the west side of I-75 or in the median areas north of the I-75/575 interchange, he said.
Will the reversible lanes pay off for commuters?
Yes, he said.
“We predict a 30- to 40-minute time savings by 2035,” he predicted.
Let’s hope that, if the lanes are built as planned, that he’s right.
But you’d better keep your fingers crossed on that.
Bill Kinney is associate editor of the Marietta Daily Journal.