Bivariate time-periodic Fokker-Planck model for freeway traffic F. Lenz, D. Herde, A. Riegert and H. Kantz Eur. Phys. J. B, 72 3 (2009) 467-472 Published online: 31 October 2009 DOI: 10.1140/epjb/e2009-00364-3