Dimitris Tselentis has successfully defended his PhD dissertation titled: Benchmarking Driving Efficiency using Data Science Techniques applied on Large-Scale Smartphone Data. This PhD thesis was carried out at the Department of Transportation Planning and Engineering at the School of Civil Engineering of the National Technical University of Athens under the supervision of Prof. George Yannis, with the support and data from OSeven Telematics. The main objective of this PhD is to provide a methodological approach for driving safety efficiency benchmarking on a trip and driver basis using data science techniques. It also investigates the way to achieve this by defining a safety efficiency index based on travel and driving behaviour metrics collected from smartphone devices. Furthermore, the present doctoral research proposes a methodological framework for identifying the least efficient trips in a database and for estimating the efficient level of metrics that each non-efficient trip should reach to become efficient. Finally, this dissertation’s objective is to study the temporal evolution of driving efficiency and identify the main driving patterns and profiles of the driver groups formed.