Warning: long, and features graphic descriptions of carnage inflicted upon COTA racing surface.
For anyone who isn't clear about what the real underlying issues are at COTA, here's an explanation I've posted before on other boards. Sorry so long, but there's really no quick way to explain it:
"Yes, it's bumpy af, even after they resurfaced 40% of the circuit in 2019-20. The soil is constantly shifting and heaving, laterally and vertically.
The roads all around the circuit go through the same problems. They're like rollercoasters. The county comes out and levels & resurfaces them every few years, but within a few months they're crazy rollercoasters again. Hell, the utility poles in the area won't even stay vertical and have to be re-installed every few years. They install them nice and plumb, but in a year or two they need to be re-set because they're leaning. They replace them over and over.
COTA Blvd is a great example, too. It was billiard table smooth in 2012 when it was built. It quickly became so bumpy that you can't drive even close to the speed limit on it without catching air in several places. No F1 cars driving out there.
If you're interested in the backstory, I wrote this about the soil problems a while back. Sorry so long, but there's no quick way to explain it.
Short version: It's very bumpy at racing speeds, esp along the east side, and is cracking/coming apart, and they aren't doing anything serious to fix the underlying problem.
Medium/long version: The ground is not very stable (putting it kindly). Really, it just never stops moving. Remember a couple of years ago when Jennie Gow reported that the teams take scans of the track on every visit, and it had moved as much as 1.5 meters in places since the previous GP there? Think about that for a second. Holy crap. That led to the all-night bump grinding ops on Friday night of the GP weekend. Seriously, wtf? There have been other bump grinding ops done prior to that as well. That helps only marginally, and thins & weakens the track surface, accelerating the appearance of new bumps & cracks in the future.
Here's the deal, in a nutshell. Unlike many other tracks, COTA will never get to a point where it's 'finished settling' and then be relatively stable.
This isn't normal settling that can be remedied by repaving every few years as at other circuits. There are massive problems with shifting soil/clay there, which was known even before they took the first core samples. The soil in that area basically never stops moving. COTA's track surface is not going to eventually settle and be stable going forward.
The black clay out there is extremely porous and expansive, expanding like a sponge in wet weather and shrinking in dry, hot weather. When it expands, it heaves and moves laterally. When it shrinks, it moves again and cracks.Long story a little shorter: the engineers knew about it and put an engineering solution in place to limit the issues. They dug down as much as 20 feet in places and laid an impermeable polymer barrier, then refilled it all with prescribed, imported road base aggregates, then paved on top of that.
The track is built along the side of a hill. A drainage solution was designed to divert rain runoff down the hill - under the track and under the water barrier. This way, the engineers sought to create a 'tube' on which the track would rest and which would be made more stable than the surrounding soil by controlling the water content inside it. Great in theory. Not so much in execution.
The theory was probably good, but what we've heard from multiple sources is that Epstein went cheaper and smaller on the drainage system than what was recommended by the engineers. Then when big rain events predictably occurred, the downsized drainage system was overwhelmed. Water is always going to find a way downhill, no matter what, so it ran across, under, and even through the now-damaged subsurface barrier 'tube'. The water moving inside the tube weakened the track base and caused subsidence. That created bumps and cracks in the surface. You can see evidence of this during any significant rain at COTA, as water weeps up from the track base (where it's not even supposed to be) and out through cracks in the track surface.
I've taken photos the last few years of water weeping up from under the asphalt, through cracks in the track. Last night, I was texted another such photo by a buddy who was out there yesterday. The photo shows water weeping up & out through cracks in the asphalt at one of the problem areas, between turns 9 and 10. The last rain out there was over a week ago and water was still weeping out onto the track yesterday.
That area is one of the segments that was resurfaced in January 2020. Other areas where we've noticed such weeping are downhill of turn 1, all along the esses, at turn 10, around turn 11, along the back straight, and around turns 17-20. In January 2020, they did some work on the deteriorating track surface. A lot of people think they resurfaced the whole thing, but they actually only resurfaced about 40% of the track, inexplicably ignoring some of the roughest areas (as noted by Tony Kanaan during IndyCar 'spring training). It's still very bumpy along the east side of the circuit (T2-11).
They claimed at the time that they were going to address the underlying drainage system deficiencies that are a big part of the problem. True to form for COTA, they ignored the drainage system and, as we predicted, the newly-resurfaced areas soon had big new bumps and cracking problems (that are actually just continuations of the same problems they've always had and have never addressed in any serious way). They ended up resurfacing some of those newly-paved areas once and even twice more in the following months, because the bumps & cracks kept coming back so quickly."
From the Jan 2020 IndyCar test. There was also actually weeping that day farther up at the 10 apex and beyond. It never dried up, all day, and the weather was dry that day. I have many more pics of large networks of deep cracks in the surface that you can't see on TV, and of weeping at T1-2 and T18-19, but they're all in different albums all over the place.
This pic is from 2 months later, several days after any rain out there.
Edited by AustinF1, 02 October 2021 - 17:13.
