  Using computer simulations, we show that metastable states still occur in
two-lane traffic models with slow to start rules. However, these metastable
states no longer exist in systems where aggressive drivers (\textit{which do
not look back before changing lanes}) are present. Indeed, the presence of only
one aggressive driver in the circuit, triggers the breakdown of the high flow
states. In these systems, the steady state is unique and its relaxation
dynamics should depend on the lane changing probability $p_{ch}$ and the number
of aggressive drivers present in the circuit. It is found also that the
relaxation time $\tau$ diverges as the form of a power-law : $\tau\propto
p_{ch}^{-\beta}, \beta=1$.
