A European passenger car talking to a US pick-up truck is shown at a joint EU-US stand at the current World Congress on Intelligent Transport Systems (ITS) in Vienna. The European Car sends an Emergency Electronic Brake Light message to the pick-up which understands it and warn its driver about the emergency braking ahead. Although both cars involved in this ‘cooperative mobility’ instance do not exactly 'speak' the same language, they can 'understand' each other thanks to EU-US harmonization efforts carried out over the past three years with the aim to bring these systems more quickly and cost-efficiently onto the roads. The joint EU-US efforts allow the use of the same communication hardware (platform) on both sides of the Atlantic, resulting in a decrease of system costs for carmakers, quicker deployment of applications based on car-to-car communication and finally lower costs for vehicle buyers. The platform can be used for a host of other messages as well, and it goes without saying that it also works in the other direction (US vehicle to EU vehicle), i.e. it is fully bi-directional.