Editing Single-point urban interchange (section)

===Advantages===
The most commonly cited advantages of SPUIs are improved operation efficiency and safety as well as reduced right-of-way requirements compared to other interchange forms.<ref name=bonneson>{{cite journal |last= Bonneson |first= James A. |date=January 1993 |title= Bridge Size and Clearance Time of Single Point Urban Interchange |journal= Journal of Transportation Engineering |publisher= American Society of Civil Engineers |volume= 119 |issue=1 |pages=77–93 |doi=10.1061/(ASCE)0733-947X(1993)119:1(77) |issn= 0733-947X}}</ref>  Left-turning traffic from both directions of the intersecting roadways is able to turn simultaneously without crossing the path of the opposing left turns. Because traffic passing through the interchange can be controlled by a single signal, vehicles can clear the intersection much more quickly than in a diamond interchange (which requires two sets of traffic signals).

SPUIs also allow for wider turns, easing movement for large vehicles, such as trucks and RVs. Furthermore, a SPUI takes up considerably less space than a full [[cloverleaf interchange]], allowing construction to take place on a limited amount of property and minimizing state use of [[eminent domain]].<ref>{{cite web |author= St. Louis District |publisher= Missouri Department of Transportation |url= http://www.modot.org/stlouis/links/SPUIFrequentlyAskedQuestions.htm |title= Single Point Urban Interchange Frequently Asked Questions |access-date= July 15, 2012 |archive-date= July 23, 2012 |archive-url= https://web.archive.org/web/20120723034644/http://www.modot.org/stlouis/links/SPUIFrequentlyAskedQuestions.htm |url-status= live }}</ref>

Finally, SPUIs are reportedly safer than other space-efficient interchange forms, such as (standard) diamond interchanges. Research suggests that, although there may not be a significant difference between the two types of interchanges in terms of total collisions, the injury and fatality rates are notably lower for SPUIs than diamond interchanges.<ref>{{cite journal |first1= Joe |last1= Bared |first2= Alvin |last2= Powell |first3= Evangelos |last3= Kaisar |first4= Ramanujan |last4= Jagannathan |date=May 2005 |title= Crash Comparison of Single Point and Tight Diamond Interchanges |journal= Journal of Transportation Engineering |publisher= American Society of Civil Engineers |volume= 131 |issue= 5 |pages= 379–381 |doi= 10.1061/(ASCE)0733-947X(2005)131:5(379)  |s2cid= 110625815 |issn= 0733-947X}}</ref>