page_title: Interchange (road)
section_title: Single-point urban interchange
hierarchical_section_title: Interchange (road) / Service interchange / Single-point urban interchange
context_page_description: In the field of road transport, an interchange is a road junction that uses grade separation, and typically one or more ramps, to permit traffic on at least one highway to pass through the junction without interruption from other crossing traffic streams. It differs from a standard intersection, where roads cross at grade. Interchanges are almost always used when at least one road is a controlled-access highway or a limited-access divided highway, though they are sometimes used at junctions between surface streets.
context_section_description: A single-point urban interchange, often abbreviated to SPUI, is a modification of the diamond interchange and has its ramps meet at one point, usually on the overpass/underpass of the non-highway. This requires only one set of traffic signals, increasing its efficiency and capacity when compared to a diamond.
  Freeways in the Phoenix, Arizona metropolitan area are great examples of the utilization of SPUI interchanges. Some examples of SPUI are along Arizona State Route 51 from Downtown Phoenix all the way to Loop 101, another location where SPUI is common.
  
  Some single-point urban interchanges have appeared in rural areas, such as U.S. Route 23 with State Highway 59 in the U.S. state of Michigan. Therefore, while "single-point urban interchange" is the most common name for this type, it is sometimes (and more accurately) called a single-point diamond interchange instead.
caption: Single point urban interchange (SPUI)