If you drive over 20 mph (miles per hour) over the speed limit you are consider reckless driving at that point. It is reccomended that you drive only 5 mph over the speed limit.
Mountain ranges are formed by a variety of geological processes, but most of the significant ones on Earth are the result of plate tectonics. Mountain ranges are also found on many planetary mass objects in the Solar System and are likely a feature of most terrestrial planets