Stockholm’s subway system is considered one of the longest art galleries in the world.Each station has its own identity, but at the same time, all metro stations have the sameuniform functional light approach.This light could not prevent the passengers from gathering and walking randomlyat the subway station’s platform. Moreover, the uniform light is neglecting the artwork onthe station’s platform; hence, this could lead to losing the identity feature of the station. Ingeneral, the demand for using public transportation in sustainable urban cities is increasing.This thesis studies how to use light as an information giver for the passengers on the subwaystation platform:By creating light safety zones and by enhancing the wayfinding to minimize conflict points.From the result of the questionnaire and the observations in two case studies, adesign principle with eight parameters has been developed to be applied in new lightingdesign for the T-Centralen platform station. It aims to restore the identity of the station,and create different zones at the T-Centralen subway platform, to enhance the movementof the passengers and to make it more organized by combining different layers of functional,atmospheric and dynamic light.