Vectors and stuff. Maybe throw a tensor or two in there? Or the Lagranian and Hamiltonian and get it right. Given the choice of two small metal boxes in a field of nearby similarly massive and much more massive objects with positive and negative relative velocities, you really choose the one with the greater velocity as “safer”? Right after you bounce off that truck your next hit may well be one going in the other direction. Or something concrete. Seems pretty clear cut to me (and is backed up by decades and millions of deaths over the last 100 years).