What is another word for grade separation?
Pronunciation: [ɡɹˈe͡ɪd sˌɛpəɹˈe͡ɪʃən] (IPA) 
Grade separation refers to the separation of different levels of transportation infrastructure to avoid crossing, which is an important safety measure. There are several synonyms for grade separation, such as overpass, underpass, flyover, overbridge, underbridge, and grade-separated junction. Overpass and flyover are interchangeable terms that refer to elevated sections of a road or railway over another road or railway. By contrast, underpass and underbridge refer to a section of a road or railway that goes underneath another road or railway. Grade-separated junction refers to a highway interchange in which the roads or railways are separated by different levels. Using these terms interchangeably can help to clarify the type of grade separation being referred to.
