Adam N. Satterfield
Executive Vice President, Chief Financial Officer and Assistant Secretary at Old Dominion Freight Line
Yeah. And I'll come back to that. Let me just address that the second quarter to third quarter change, you're right. The pure math is -- is more about a 10 basis-point change, but there are a couple of years in there that -- that skew that. In '23, last year -- obviously, we had a major acceleration in revenue that allowed us to improve the operating ratio 170 basis points from 2Q to 3Q, and then 2020 was similar, where -- you had the COVID cliff that happened and then the reacceleration of business levels. So when I just look at more of a normalized -- kind of progression, that's typically -- what we'd expect unless you've got something unusual going on -- that -- that would drive some change there.
With respect to the -- the tonnage question and -- and shipments, I mean, obviously, as you said -- we're -- we're -- we had the -- the acceleration that was meaningfully happening last year. If you recall, we were at 47,000 shipments per day, really from December of -- of '22 through July of -- of '23, and immediately stepped up to about 50,000 in August and then accelerated further to 51,000 in September.
So you know, step function change that would be well above anything that was really happening with the underlying economy, if you will. So -- if -- if we can see some type of -- of normal acceleration, if you will, just like from a tonnage standpoint, our 10-year average from July to August is 0.6% [Phonetic] increase there, and then about a 3.5% increase in September.
So -- we'll -- we'll see how that goes. But -- right now, if -- even if you hit those, it would look like you would have -- negative change in those volumes. But -- overall, I think it's just as we look at things sequentially, maybe more so than just a year-over-year given that challenge is what can we achieve relative to what normal seasonality would be. And -- and what we've seen, at least so far, through -- through July.
From a tons per day standpoint just from a pure quarter, we're typically up about 1%. And -- when we gave the numbers earlier, but in the -- the second quarter, that average is just call it 6% and we were up 3%, just sort of rounding numbers. So we were up kind of half of -- of what normal seasonality would suggest. So we -- we've got to make up some ground. Like I said earlier, we always lose a little bit of business in July and that's normal. And so if we can have kind of a little bit of acceleration through August and -- and then see some -- some acceleration into September -- we were almost at normal seasonality in the June period.
And so -- and the same thing with March, you got to adjust for the good Friday. But we're about at seasonality in those stronger growth months of the quarter. So if we can make some progress in August and then see some sense of that -- that strong acceleration through the month of September -- I think we'll be okay. And we've -- we've positioned ourselves well. You know, whenever we -- we come out of this true economic downturn, you know, we're -- we're operating at a 72%, essentially, and 71.9%. I guess I should take credit for every basis point we -- we have in -- in terms of where we've operated.
And when I look at the breakdown of our operating ratio in the quarter and -- and where we are from an overhead standpoint relative to our direct variable cost, I'm really pleased with the improvement that we've made with our direct cost performance. And -- and that just gets into the day to day management -- within our operations in the field, primarily.
And -- but everyone is -- is contributing to that overall operating ratio. And -- but our overhead cost have increased there, 20% to 21% of revenue in the most recent quarter. You know, those costs have been down to around 17% in the past. So, you know, once we get some true density coming back into the -- the network, we've -- we've built our network and our system to accommodate more than 50,000 shipments a day. So once we get back into, you know, 50,000, 55,000, 60,000, whatever that number is, that's where you'll really see the -- the power of -- of operating density in the model.
And you move that scale from 20% to 21% back towards 17% -- that puts us back in -- in the -- with an OR with the 6 handle [Phonetic] on it, back where we were in 2022. So -- it's -- I think we're in a great spot and have managed through this -- this downturn very well, and have certainly put ourselves in a great position to capitalize on the market when we actually start seeing some -- economic wins at our back.
