On a highway filled to capacity by human drivers which is about 2,200 vehicles per hour per lane, about five percent of the available road space is taken up by cars. Five percent. This is because humans are so bad at driving that we need lanes that are twice the size of our cars, and at highway speeds, we have to keep between 40 and 50 meters away from the car in front of us.
via Study: Intelligent Cars Could Boost Highway Capacity by 273% – IEEE Spectrum.
This concept is tangentially related to Smoothy in improving highway (long road) capacity and efficiency. Our concept can be implemented without hardware changes to the vehicles. This concept can be implemented if all cars are equipped with adaptive cruise control. Both are technically possible today. However, our concept of course has limited scope and effectiveness. The trade-offs between infrastructure change and effectiveness are apparent.