They’re not writing in binary. They’re defining a base 10 number that is 0.11, followed by a single 0, then 1, then two 0s, then 1, then three 0s, then 1, and so on. The definition ensures that it never repeats, but because it only contains 1 and 0, it would never contain any sequence with the numbers 2 through 9.

Maybe the cyclists don’t like the stop signs that the path frustratingly has but the road does not? Around that stop there are two within a few hundred metres, and frequently stopping (or slowing down fot a rolling stop) makes riding slower and more tiring. That’s probably not nearly the entire motivation, though.