摘要： With the advent of LED technology, lighting studies have gained a great interest, especially street lighting. Nowadays, these studies demonstrate the great energy savings achieved by replacing high pressure sodium lamps with LED. As LED technology is continuously improving, energy savings are increased and thus the payback time of the investment is decreasing more and more. However, there are a lot of cases were the public constructions are delayed and the initial lighting design is getting obsolete, due to the energy efficient upgrade of the LEDs. In this research a newest version (2019) for the lighting design was performed using the latest technology of LED street lighting and compared with the one performed in 2017. Egnatia Odos EO, the largest national road in Greece, was selected as the case study for both studies (2017 and 2019). EO covers a distant of 670 km in northern Greece. Existing lighting infrastructure was designed and installed 17 years before, according to the previous version of EN12301 [1-3].