  The analysis of the radial distribution function of a system provides a
possible procedure for uncovering interaction rules between individuals out of
collective movement patterns. This approach from classical statistical
mechanics has revealed recently the existence of a universal scaling in systems
of pedestrians, provided the potential of interaction $V(\tau)$ is conveniently
defined in the space of the times-to-collision $\tau$ [Phys. Rev. Lett.
\textbf{113}, 238701 (2014)]. Here we significantly extend this result by
comparing numerically the performance of completely different rules of
self-avoidance in bidirectional systems and proving that all of them collapse
to a common scaling both in the disordered phase ($V(\tau) \sim \tau^{-2}$) and
in the lane-formation regime ($V(\tau) \sim \tau^{-1}$), so suggesting that
these scalings represent actually a universal feature of any self-avoiding
bidirectional flow.
