In this paper, we focus on car traffic simulation and optimization of a portion of the Salerno urban network in Italy. The car densities evolution is described by a fluid dynamic model. A cost functional, that measures the kinetic energy on roads, is maximized using a decentralized approach. In particular, to improve viability conditions, we apply locally optimal distribution coefficients at each 1x3 junction (one incoming road and three outgoing roads) and optimal right of way parameters at each junctions 2x1 (two incoming roads and one outgoing road). The goodness of the optimization results has been confirmed by simulations