That's actually not quite true. You can certainly build a new road that will lighten up traffic. Traffic engineering is a rather serious and complicated scienc

That's actually not quite true. You can certainly build a new road that will lighten up traffic. Traffic engineering is a rather serious and complicated science, the demand on a road can fluctuate based on hundred of factors such as the time of year, weather condition, urban development, population size and density, time of day, weekday, the kind of radio everyone is listening to, tailgating fractions, etc etc etc. Building a road requires some serious thought into how to build it so that not everyone jumps on the new road while also not preventing anyone from using it. For all conditions.