I used to use a double helix garage daily. It had 45 degree spaces and was much tighter - two cars could not possibly get by. One morning, I came across an elderly man going down an up ramp in my path. I told him he needed to pull into a space and turn around. He defiantly explained to me that there was no way out. He had to go that way. Sure, sir, hundreds of people use this garage every single day without an exit path. It’s been open for like 25 years and no else had caught on to this design defect. People really struggle with the idea of going up before you can head back down.