  The traffic flow through a light signal is explored by using the optimal
velocity model and its improvement known as full velocity differences model.
The simulations consider a single line of identical cars, equally spaced, and
with no obstacles after the signal crossing line. The flow dependence on
vehicle's characteristics, as it's length and sensitivity, are studied. Also,
the influence of the attitude of drivers (careful or aggressive) has been used
as parameters on the present work. It was found that the optimal separation
between cars, defined as the distance that allows the system to carry the
higher number of vehicles through the signal crossing line, is independent of
the sensitivity of the system, but it does depend on the aggressive or careful
characteristic of the drivers. The optimal separation is also found to be
proportional to the length of the cars for a system of identical vehicles.
