This book constitutes the proceedings of the 14th International Workshop on Communication Technologies for Vehicles, Nets4Cars/Nets4Trains/Nets4Aircraft 2019, held in Colmar, France, in May 2019. The 9 full papers and 1 short paper in this volume were carefully reviewed and selected from 15 submissions. The volume features contributions in the theory or practice of intelligent transportation systems (ITS) and communication technologies for: - Vehicles on the road: e.g. cars, trucks and buses; - Air: e.g. aircraft and unmanned aerial vehicles; and - Rail: e.g. trains, metros and trams.