While trains aren't high on the list of American travel trips, road trains may be a concept that pops up on the travel scene within a few years.

A is a developing technology that enables a line of cars to follow a large van or truck driven by a professional human driver. The cars, programmed to follow the lead truck's every move, will follow each other very closely in a long train that not only cuts down on fuel consumption for the cars (since they encounter far less aerodynamic drag as they cruise in the slipstream of the cars and truck in front of them) but also compresses more cars in a smaller area of road.

Because of the automated nature of the road train, passengers and drivers alike can sit and relax in the comfort of their own cars and let the head of the train do all of the driving. Drivers can read, eat, work on a mobile device, whatever they want -- all while maintaining a steady pace. When they want to leave the train, drivers simply take control of the vehicle and pull out from the train onto an off ramp.

This technology is still being worked on by various car makers in Europe -- Volvo being one, as you can see in below -- who are trying to work out the kinks in the process.

If successful, this might be a huge application of technology for Americans, since we have a vast network of roads, but sometimes don't have the stamina to make the trips across the country.