It is shown how to explicitly coarse-grain the microscopic dynamics of the
Vicsek model for self-propelled agents. The macroscopic transport equations are
derived by means of an Enskog-type kinetic theory. Expressions for all
transport coefficients at large particle speed are given. The phase transition
from a disordered to a flocking state is studied numerically and analytically.Comment: 4 pages, 1 figur