Superstreet

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At a superstreet, all traffic on the side road must turn right, where it can access a U-turn ramp. Traffic on the main road can turn left directly. The opposite applies for countries that drive on the left.

A superstreet, also known as a restricted crossing U-turn (RCUT), J-turn,[1] or reduced conflict intersection,[2] is a type of road intersection that is a variation of the Michigan left. In this configuration, traffic on the minor road is not permitted to proceed straight across the major road or highway. Drivers wishing to turn left or go straight must turn right onto the major road, then, a short distance away, queue (wait) into a designated U-turn (or crossover) lane in the median. When traffic clears, they complete the U-turn and then either go straight or make a right turn when they intersect the other half of the minor road.

The superstreet typically requires four traffic light-controlled intersections, and most traffic must pass through two of them, but each light has only two phases, greatly increasing average traffic flow; there is no need for numerous left-turn phases where most traffic is waiting for only a few cars to clear the intersection. Turning movements on roads with lower cross-traffic volumes may be controlled with stop or yield signs for turning traffic rather than with signals.

Practicality[edit]

Superstreets are not very common because they require substantial Right of Way to provide a median that can accommodate truck traffic. Inconvenience to traffic on the minor road is mostly a perception issue and does not represent additional delay in most cases.[citation needed] However, superstreets are cheaper to construct than limited access freeways with interchanges and improve the flow of traffic on the major road.

Usage[edit]

In May 2015, a superstreet was constructed on US 41 at SR 114 on the border between Morocco and Beaver Township in Newton County, Indiana. The state of Indiana makes a distinction between an RCUT, which it defines as having a traffic light-controlled main intersection, and a J-turn, which it defines as having the main intersection controlled by stop or yield signs.[3] Two examples of what Indiana calls a "J-turn" opened on June 30, 2016 at the intersections of US 231 with IN 62 and IN 68 near Dale. Traffic on the state roads at both intersections can only turn right, while US 231 traffic can turn left at both intersections.[4]

Troy, Michigan has a superstreet on West Big Beaver Road at Lakeview Drive. 42°33′41″N 83°10′53″W / 42.561383°N 83.181310°W / 42.561383; -83.181310

Lake Elmo, Minnesota has a superstreet intersection on MN 36 at Keats Avenue (45°02′08″N 92°54′14″W / 45.0356°N 92.9038°W / 45.0356; -92.9038).[citation needed]

In North Carolina, five superstreet intersections were included as a part of U.S. Route 17's recent upgrades near Wilmington, North Carolina (34°12′58″N 78°01′08″W / 34.21603°N 78.018969°W / 34.21603; -78.018969).[citation needed][when?] There are also three superstreet intersections in Holly Springs along the NC 55 bypass.[5]

In 2011, Ohio State Route 4 Bypass in Butler County, Ohio, was reconfigured with three superstreet intersections.[6] The Ohio Department of Transportation is also planning to build a superstreet on US 127 at Kruckeberg Road in Greenville Township, Darke County beginning in summer 2019. (ODOT materials term this a "partial" RCUT, contrasting it with an "RCUT", even though the illustrations of the "partial" RCUT look identical to the configuration otherwise described in this article as an RCUT.[7] It would appear that what Ohio is terming an "RCUT" is a configuration the Federal Highway Administration has called a "basic RCUT", which prohibits left turns from the major road, restricting movements to right-in/right-outs and median U-turns only.)[8]

In Texas in 2010, several intersections on US 281 were converted to superstreet in the northern San Antonio neighborhood of Stone Oak, north of Loop 1604, to relieve rush hour congestion.[9][10][11] In northwest San Antonio in 2011, two intersections on Loop 1604, north of State Highway 151, were converted to superstreet.[12][13] These intersections, however, were demolished when 1604 was upgraded to freeway status in the area. In Austin, a superstreet is being phased in starting February 19, 2013, at the intersection of SH 71 and Farm to Market Road 973 east of Austin-Bergstrom International Airport not far from the eastern boundary of the Austin city limits. This becomes the city of Austin's first superstreet and the second city in Texas to feature this intersection design.[14]

Benefits[edit]

A study showed a 20 percent overall reduction in travel time compared to similar intersections that use conventional traffic designs; intersections experience an average of 46 percent fewer reported automobile collisions – and 63 percent fewer collisions that result in personal injury.[15]

See also[edit]

References[edit]

  1. ^ Staff (October 2009). "Techbrief: Restricted Crossing U-Turn Intersection (FHWA-HRT-09-059)". Alternative Intersections/Interchanges: Information Report (AIIR) (FHWA-HRT-09-060). Federal Highway Administration. Retrieved August 24, 2012. 
  2. ^ Minnesota Department of Transportation, Reduced Conflict Intersections, accessed November 2014
  3. ^ "Traffic Operations: Median U-Turns". Indiana Department of Transportation. Retrieved June 24, 2017. 
  4. ^ Taylor, Britney (June 29, 2016). "J-Turns At U.S. 231 Intersection To Open Near Dale, Indiana". Evansville, Indiana: WEVV-TV. Retrieved July 10, 2017. 
  5. ^ Kenney, Andrew. "Traffic rolls onto new Holly Springs superstreet". News & Observer. Retrieved 3 December 2013. 
  6. ^ "State Route 4 Bypass Widening". Butler County Transportation Improvement District. July 21, 2011. Retrieved December 11, 2017. 
  7. ^ Martin, Erik (June 15, 2017). "State agrees to fund 127/Kruckeberg intersection reconstruction". The Daily Advocate. Greenville, Ohio. Retrieved June 17, 2017. 
  8. ^ Staff (March 8, 2016) [April 2010]. "Report: Chapter 4. Restricted Crossing U-Turn Intersection (FHWA-HRT-09-060)". Alternative Intersections/Interchanges: Informational Report (AIIR) (FHWA-HRT-09-060). Federal Highway Administration. Retrieved June 24, 2017. 
  9. ^ New, Brian (March 11, 2010). "Super street construction on US 281 to begin on Monday". KENS. Retrieved March 23, 2013. 
  10. ^ "US281 Superstreet". 4-1-1 on 281. Alamo Regional Mobility Authority. Retrieved March 23, 2013. 
  11. ^ "Loop 360 - Archive: Innovative Intersections: The Superstreet (RCUT)". Texas Department of Transportation. Retrieved March 23, 2013. 
  12. ^ "Loop 1604 Super Street". Alamo Regional Mobility Authority. Retrieved March 23, 2013. 
  13. ^ "Loop 1604 superstreet promises easier flow". KENS. September 15, 2011. Retrieved March 23, 2013. 
  14. ^ "Super street coming to East Austin". Austin, TX: KVUE-TV. February 19, 2013. Retrieved February 19, 2013. 
  15. ^ PhysOrg: No left turn: 'Superstreet' traffic design improves travel time, safety

External links[edit]