2005/03/17 by B. Schmittmann, J. Krometis, R. K. P. Zia
Physics and Astronomy · #cond-mat.stat-mech #physics.soc-ph
paper · pdf · doi:10.1209/epl/i2005-10006-6
published as Europhysics Letters 70, 299-305 (2005) · 7 pages, 3 figures; to appear in Europhysics Letters (2005)
arxiv created 2005/03/17 · arxiv updated 2009/12/01
Motivated by an analogy with traffic, we simulate two species of particles (`vehicles'), moving stochastically in opposite directions on a two-lane ring road. Each species prefers one lane over the other, controlled by a parameter 0 ≤ b ≤ 1 such that b=0 corresponds to random lane choice and b=1 to perfect `laning'. We find that the system displays one large cluster (`jam') whose size increases with b, contrary to intuition. Even more remarkably, the lane `charge' (a measure for the number of particles in their preferred lane) exhibits a region of negative response: even though vehicles experience a stronger preference for the `right' lane, more of them find themselves in the `wrong' one! For b very close to 1, a sharp transition restores a homogeneous state. Various characteristics of the system are computed analytically, in good agreement with simulation data.