Every year, billions of vehicles worldwide shed an estimated 6 million tons of tire fragments. These tiny flakes of plastic, generated by the wear and tear of normal driving, eventually accumulate in the soil, in rivers and lakes, and even in our food. Researchers in South China recently found tire-derived chemicals in most human urine samples.
There are some vehicles that go on iron wheels, on a special kind of iron road that are very efficient. Only bad parts are costly initial investment and difficulties to scale up if the existing network gets overloaded (such as the Swedish rail system who has been over “maximum” capacity for a long time which has put needed maintenance on hold at many places)