The word "throughway" is a transparent Modern English compound, formed by directly combining the native English words "through" and "way." Its logic is entirely literal, describing a road or path that allows one to travel through from one point to another without obstruction. This term emerged in the 20th century, specifically in American English, to name a new type of high-speed, limited-access road designed for unimpeded, direct travel. It is a synonym for "expressway" or "thruway," with the latter being a trademarked name that popularized the clipped spelling.

Structure: through (passing from one side to the other) + way (road, path) - through: From Old English þurh, meaning "from one side to the other, by means of." Functional role: Adjective/Adverb root conveying the concept of direct passage. - way: From Old English weg, meaning "road, path, course of travel." Functional role: Noun root denoting a route or thoroughfare.