ConwayLife.com

To be honest, a better name could be the grader.
It also has some variants, like:
x = 64, y = 64, rule = B2/S23
bo$2bo2bo$b$3b2o!
Or:
x = 64, y = 64, rule = B2/S23
6bo$2bo2bo$b$3b2o!
I like the grader because it produces an almost undisturbed path, and the original lays two lines with a bigger line ...

I accidentally found this in B2/S23. I don't know what to call it and someone else has probably found it already. Also, I have barely used the game of life at all.
I call it the road layer.