The aim of this paper is the investigation of the critical factors affecting travel time in Athens, Greece, during the pilot implementation of the Athens Great Walk, a series of novel traffic and parking interventions for the city center. Travel time data collected in 12 routes using Google Maps API which were combined with traffic and pedestrians volumes and road geometry characteristics. Five linear and lognormal regression models were developed to determine the factors that affect the travel time on five road types. The results revealed that the factors affecting travel time are significantly related to the motorized traffic, active transport modes as well as road geometry characteristics. The passenger car share affects negatively the travel time in four of the five road types. The bus share and pedestrian traffic are significantly affect the travel time in three road types.