One constant throughout today's two practice sessions was the drivers' criticism of the bumps at various parts of the Circuit of the Americas.
The bumps are the result of a number of reasons, not least some parts of the track 'shifting', and while organisers have done their best over the years to resolve the issue this year they appear to be worse than ever.
While they are thought to have caused several of the spins and offs witnessed over the course of the day, the bumps are also thought to have caused issues with the cars, Charles Leclerc, who suffered a throttle issue in FP1 linked to the bumps, being told repeatedly in FP2 to shift gear before the bump at Turn 9, only for the Ferrari driver to insist that he was doing so.
One of the harshest critics was Lewis Hamilton, who described the bumps as dangerous and the track as the bumpiest he has ever raced on. At session end, the world champion elect admitted that he was suffering a headache as a result of the bumps, the worst of which can be found at Turns 1, 9 and 16.
"It was the bumpiest track by far that I have ever been on," the Briton told reporters. "I had such a headache.
"For people to understand when we talk about bumpy tracks, the bumps are not such a bad thing in some places because it just adds character to a circuit," he explained. "So I'm not a fan of completely smooth circuits. But this one is like massive, massive bumps, and the problem for us is that we don't have much suspension. Our suspension moves like this much, so it's usually your butt on the floor, and your spine takes all the compression, so I was feeling horrible. I had a massive headache after P1, I had to lay down, I was not feeling great."
"You have to be careful," said Max Verstappen. "If you go a bit off-line and you want to out-brake someone, I'm always a little bit afraid to damage your back or whatever.
"It's something we have to look into of course," he added. "I don't mind bumps on a street circuit, it's part of it. But these bumps are quite severe. It's almost like a hump or a ramp in some places where the wheels are coming off the ground. That's of course not what you want. We'll have a look at it."
"It can be very painful," said Sergio Perez. "Someone can get hurt over these bumps and you have seen some drivers going off at very high speed, and it is due to the bumps. I think it is totally unacceptable.
"Today we are over the limit," he continued. "We have seen some incidents due to the bumps and I think that is just not acceptable. In the race, and I hope not, but I expect to see some people crashing out when the deg starts to kick in. All of a sudden you get a bump in the wrong angle and go straight into the wall, so it is quite bad."
"They've got to sort it out for next year, I don't think there's a solution for this year but going forward, there's two or three bumps they've got to remove. They're like speed bumps out there so it's too much. I think when you hit the rev limiter and get a bit of air it's a little bit much. It's more for the rally cross boys than for us."
Check out our Saturday gallery from Austin, here.