Air travel is not the only headache caused by the monster storm sweeping the U.S. Hundreds of miles of interstate highways are also closed, some for the first time in years. Both Interstate 29 and Interstate 90 are closed in South Dakota, where winters are always tough. Interstate 94 is also closed in the western part of the North Dakota, and travel is not advised on that state’s segment of Interstate 29, which runs north-south. In Minnesota, Interstate 90, which runs east-west, is also closed, making it impossible for anyone whose flight is canceled to easily travel by land. Local officials warn people against any travel at all due to the extreme low temps, which can cause frostbite within a few minutes of exposure. More than 200 million people will be under alerts for severe wind chill, including states known for mild winters. The National Weather Service’s Watch Warning graphic describes the extreme weather event as producing the highest number of winter weather warnings and advisories “ever.”