In recent years, LEDs are offered as "energy efficient" lighting solutions for road lighting by being highlighted as low energy consumer with higher economic lifetimes. The applicability of LED road lighting luminaires should be considered only if they can provide the required lighting quality criteria. In this study, a model road geometry is chosen as M3 lighting class in order to realize design calculations by fulfilling the required lighting quality criteria for comparison with conventional lighting installations having high pressure sodium and metal halide lamps. The photometric data and prices for LED luminaires to be used in the calculations are obtained from the well-known manufacturers in all around the world and the most energy efficient LED luminaire is determined. Cost analyses are realized based on the most efficient LED luminaire and compared with conventional lighting luminaires in terms of installation, operation and maintenance costs. Finally, optimum solutions are investigated by considering different prices and efficacy factors for LED luminaires.