Self-driving vehicles are useful for hauling both people and cargo, but you can usually only prioritize one of those tasks unless you can afford to buy separate vehicles. Mercedes-Benz might have a solution to the problem: build a machine that can change its role on demand. Its Vision Urbanetic concept van uses a modular body system to switch between people-carrying and cargo duties, with an electric-powered platform underneath. If you need a ridesharing service or shuttle bus, a passenger module can take up to 12 people while providing a dramatic view of the road. If you need to ferry goods across town, however, the cargo module fits as many as 10 European-sized pallets inside a boxy, no-nonsense frame. A company or public agency could serve two sets of customers without having to buy separate fleets for each. And you wouldn’t need to put all the modules in the same place — the base vehicle can travel without any module attached.