There's no way they could have stopped in time approaching an intersection at that speed.
It's a testament to modern car safety that anyone survived this brutal crash in an Audi RS3 at triple digit speeds. As technically advanced as Audi's sport wagon is, nothing could have prevented this accident from happening at the speed they were going. On-board footage shows the driver of the Audi RS3 hurtling down streets in Belgium at breakneck speed. They were going so fast that they failed to see the stop sign warning them of an incoming intersection.
Realizing their mistake too late, they slam on the brakes. But by the time they reach the sharp turn they're still doing 124 mph. The RS3 veers off the road and goes airborne before violently rolling over several times in a nearby field. It's rather fortunate there were no houses in their path, or the accident could have been far more devastating.
Looking at photos showing the battered remains of the RS3, it's staggering that the driver survived the brutal accident without sustaining any serious injuries. Judging from the extensive damage, the hot hatch is a complete write off. As for why there are race track-style barriers, gravel traps and tire walls surrounding the road, the accident took place on the former Chimay Street Circuit in Belgium, which hosted the Grand Prix des Frontieres until it ended in 1972 for safety reasons. A shortened version of the race track is occasionally used for bike racing, but otherwise it's primarily used as a public road.
It's possible that the driver had never driven down the former race circuit before so didn't anticipate that there would be a sharp 90 degree turn after the high speed straight, but that still doesn't excuse their lack of awareness.