What factors influence interchange type selection for freeway systems?

Interchange selection considers: (1) Traffic volumes and patterns - directional splits, turning movements, ramp capacities, (2) Site constraints - ROW, topography, adjacent development, (3) Geometric standards - ramp grades, weaving lengths, acceleration/deceleration distances, (4) Intersection spacing - affects weaving and sign placement, (5) Cost - structures, earthwork, ROW acquisition. Types: diamond (simplest, lower capacity), partial/full cloverleaf (continuous flow, large footprint), directional (highest capacity, most expensive), SPUI (compact, good for diamonds). System vs service interchanges have different criteria.