An interchange is a grade-separated junction where two or more roads meet without crossing at the same level, using ramps to connect traffic flows between roadways. Common interchange types include: cloverleaf (loop ramps in each quadrant), diamond (ramps connecting to a surface crossroad), and various modern configurations designed for safety and efficiency. Interchanges eliminate the delays and hazards of at-grade intersections for high-volume, high-speed traffic. Building interchanges is expensive due to land requirements, bridge construction, and complex geometry. Interchange locations significantly affect land use—properties near interchanges become attractive for commercial development given accessibility advantages. Municipalities typically don't control provincial highway interchanges but are affected by them: interchange capacity affects local traffic, interchange access shapes development patterns, and new or modified interchanges require coordination with local road networks. Interchange design and operational decisions involve complex engineering analysis of traffic patterns and safety considerations.