This document presents a proposed methodology of technical-economical comparison between streetlight luminaires of horizontal mounting type in High Pressure Sodium (HPS) and Solid State (LED) technologies used in pedestrian lighting systems. First, a proposed procedure to determine equivalence between luminaires of both technologies, and choose LED technology luminaires as replacement of HPS luminaires is formulated. Then, a case study is presented in which the proposed procedure is applied to a real scenario, such as a public park with passive recreation spaces and exclusive pedestrian use. The usefulness of the procedure is validated by means of photometric calculations performed with information of luminaires available in the local lighting market. Finally, an economic analysis of the possible replacement of the existing HPS luminaires in the case study scenario for LED luminaires chosen by means of the initially proposed method is carried out.