I’m pretty sure it’s the lack of curbs/kerbs those lines on the corners, so people can judge how fast they are going around the bend. Unfortunately, as far as I know, there is no definitive length so I have to wing it.

Oh yeah, this is what I did during Father’s Day and today’s lunch break. I still have to touch some stuff up, but it looks spiffy so far! Also, Hot Wheels 100% look fantastic.