Complex sentence: The U.S. Highways in Michigan are part of the United States Numbered Highways that are owned by the U.S. state of Michigan and maintained by the Michigan Department of Transportation (MDOT).
Split into simpler sentences: The U.S. Highways in Michigan are part of the United States Numbered Highways that are owned and maintained by the U.S. state of Michigan. In Michigan they are maintained by the Michigan Department of Transportation (MDOT).