  In recent years statistical physicists have developed {\it discrete}
"particle-hopping" models of vehicular traffic, usually formulated in terms of
{\it cellular automata}, which are similar to the microscopic models of
interacting charged particles in the presence of an external electric field.
Concepts and techniques of non-equilibrium statistical mechanics are being used
to understand the nature of the steady states and fluctuations in these
so-called "microscopic" models. In this brief review we explain, primarily to
the nonexperts, these models and the physical implications of the results.
