Abstract: The Interpass: Uninterrupted, Grade-Level Interchange having One-way Approach and Departure Legs is a geometric design for an at-grade interchange of one-way roadways that has no conflict points and which allows uninterrupted, uniform-velocity traffic flow. The subject invention is neither an overpass, nor an underpass, nor an at-grade intersection, nor a grade-separated interchange, and it has comparatively few of the negative qualities associated with those types of roadway junctions. Uninterrupted, grade-level interchanges of the subject design, when connected into a directed transportation network having one-way roadway segments, can constitute the nodes of an intrinsically-safe, grade-level, arterial or collector transportation facility with superior controllability, efficiency and safety, compared to those of traditional facilities.