Since the I-75 / 575 express lanes opened, many people have told me that their commute in the general purpose lanes is now 10, 15, even 20 minutes faster, each way, every day.
Data from GDOT shows that since the express lanes opened, enough people are willing to pay the tolls, that traffic flow in the free general purpose lanes is dramatically improved.
The following data compares the average traffic performance from January-February 2019 to January-February 2018.
Southbound in the general purpose lanes in the morning
♦ At the peak of morning rush hour, the lowest average speed was approximately 25 mph.
♦ The average speed was under 60 mph for approximately 9 hours 10 minutes.
♦ The average speed was under 50 mph for nearly 6 hours.
♦ The average speed was under 40 mph for approximately 4 hours.
♦ At the peak of morning rush hour, the lowest average speed was approximately 41 mph.
♦ The average speed was under 60 mph for approximately 3 hours 5 minutes.
♦ The average speed was under 50 mph slightly more than 1 ½ hours.
♦ The average speed was under 40 mph for approximately zero minutes.
♦ The average speed is now under 60 mph for a shorter duration than the amount of time that it remained under 40 mph last year!
Part of the reason why southbound traffic is so bad (worse than northbound), is because I-285 congestion backs up onto I-75 southbound.
Average speed does not mean constant speed. At the peak of rush hour, on a typical day, in 2019 the average speed bottoms out at 41 mph, but there may still be spots where someone has to slow down to 25 mph. But last year, that slowdown might have been down to 10 mph.
In some ways, the data for northbound traffic in the afternoon is less dramatic, and in other ways it is more dramatic.
Northbound in the general purpose lanes in the afternoon/evening
♦ At the peak of the afternoon rush hour, the lowest average speed was approximately 26 mph.
♦ The average speed was under 60 mph for approximately 5 hours 15 minutes.
♦ The average speed was under 50 mph for nearly 4 hours.
♦ The average speed was under 40 mph for more than 2 1/2 hours.
♦ At the peak of the afternoon rush hour, the lowest average speed is approximately 53 mph.
♦ The average speed was under 60 mph for approximately 2 hours 45 minutes.
♦ The average speed was under 50 mph for zero minutes.
♦ Obviously, even at the peak of rush hour on typical days, the average speed never gets down even close to 40 mph, vs. 2 ½ hours under 40 mph last year.
No matter how you look at the data, in both the morning and the afternoon, average speed in the general purpose lanes is dramatically faster, and the duration of rush hour congestion is dramatically reduced.
GDOT is planning additional express lanes for I-285. They are also planning to rebuild the I-20/I-285 interchange so that it will no longer back up traffic for miles. These projects will bring a lot more traffic relief to Cobb commuters.
A recent transit study, the Top End I-285 Transit Feasibility Study, recommended Bus Rapid Transit operating in the express lanes. It does not propose to build a separate set of bus lanes. If they would extend that proposal all the way down to I-20, that is a transit proposal that I think could contribute to further reducing traffic congestion.
The I-75/575 express lanes has also been a cost-effective project for taxpayers. The total cost was about $836 million. That’s a tiny fraction of what rail would have cost, and it is being utilized by a lot of commuters, and providing tremendous traffic congestion relief for everyone.
Also, in the long run, the tolls will reimburse the entire cost. Those who pay the tolls to use the road will ultimately pay for the entire cost of building the road. The tolls will also pay for maintaining the roads. No taxpayer subsidy.
So, who are the winners? Cobb commuters and Cobb taxpayers are the winners.