whats the difference between a highway and a free way
Controlled-access highway In the United States, a freeway is defined by the federal government's Manual on Uniform Traffic Control Devices as a divided highway with full control of access.[68] This means two things. First, adjoining property owners do not have a legal right of access,[69] meaning that they cannot connect their lands to the highway by constructing driveways, although frontage roads provide access to properties adjacent to a freeway in many places. When an existing road is converted into a freeway, all existing driveways must be removed and access to adjacent private lands must be blocked with fences or walls.
U.S. Route 20 U.S. Highway 20 (US 20) is an east–west United States highway that stretches from the Pacific Northwest all the way to New England. The "0" in its route number indicates that US 20 is a coast-to-coast route. Spanning 3,365 miles (5,415 km), it is the longest road in the United States,[2] and particularly from Idaho to Massachusetts, the route roughly parallels that of Interstate 90 (I-90), which is in turn the longest Interstate Highway in the U.S. There is a discontinuity in the official designation of US 20 through Yellowstone National Park, with unnumbered roads used to traverse the park.