Since my first commercial track Tandem Hobbies in Panorama City, CA I have seen a lot of tracks that might have been less than optimum. Tandem quickly replaced a short hill climb so steep that a turn marshal was there to help cars up the straightaway. They replaced it with a smooth banked over and under figure 8.
A couple miles down the road on Woodman next to the railroad tracks was a 4 lane Drag Strip banked oval. The banked turn was tight but you had the choice of 12, 18, 24 or 36 volts. What could possibly go wrong. I've been trying for years to remember the name of the place.
Hobby City in Anaheim had guide slots so narrow you could almost read through your guide by the time it would allow you to go around the track. It had nets near the ceiling to catch your car. That might have pointed to a design flaw.
So where were your tracks of infamy?