It's hard to imagine what the state of F1 in the U.S. would be like right now without Austin's Circuit of the Americas.
The purpose-built COTA racetrack has hosted the U.S. Grand Prix since 2012, which ended a run of four years without a race in the States -- F1 had left under a cloud in 2007 following a difficult stint with a race at the Indianapolis Motor Speedway, most infamously marked by the 2005 edition where all but six cars peeled into the pit-lane at the end of the pre-race warm-up lap and refused to take part due to a safety dispute.