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Interchange (road)

March 28, 2023

"Offramp" redirects here. For other uses, see Offramp (disambiguation).
"Slip road" and "Limited access ramp" redirect here. For the turn lane at an intersection, see Slip lane.

In the field of road transport, an interchange (American English) or a grade-separated junction (British English) is a road junction that uses grade separations to allow for the movement of traffic between two or more roadways or highways, using a system of interconnecting roadways to permit traffic on at least one of the routes to pass through the junction without interruption from 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 (freeway or motorway) or a limited-access divided highway (expressway), though they are sometimes used at junctions between surface streets.

The High Five in Dallas, Texas. This is a complicated five-level stack interchange, due to the proximity of frontage roads and segregated high-occupancy vehicle lanes. This hybrid design is based on parts of a four-level stack for highways, with a three-level-diamond interchange to handle the frontage roads.
32°55′27.2″N 96°45′50.0″W / 32.924222°N 96.763889°W / 32.924222; -96.763889
An aerial view of the Lakalaiva interchange in the Tampere Ring Road between the Highway 3 (E12) and Highway 9 (E63) near city of Tampere.
61°27′46″N 23°46′10″E / 61.46278°N 23.76944°E / 61.46278; 23.76944

Terminology

 
An interchange between the M0 and M4 motorways outside Budapest, showcases directional, semi-directional, and loop ramps.
47°24′18″N 19°18′55″E / 47.40500°N 19.31528°E / 47.40500; 19.31528

Note: The descriptions of interchanges apply to countries where vehicles drive on the right side of the road. For left-side driving, the layout of junctions is mirrored. Both North American (NA) and British (UK) terminology is included.

Freeway junction, highway interchange (NA), or motorway junction (UK)
A type of road junction linking one controlled-access highway (freeway or motorway) facility to another, to other roads, or to a rest area or motorway service area. Junctions and interchanges are often (but not always) numbered either sequentially, or by distance from one terminus of the route (the "beginning" of the route).[2]
The American Association of State Highway and Transportation Officials (AASHTO) defines an interchange as "a system of interconnecting roadways in conjunction with one or more grade separations that provides for the movement of traffic between two or more roadways or highways on different levels."[3]
System interchange
A junction that connects multiple controlled-access highways.[4]
Service interchange
A junction that connects a controlled-access facility to a lower-order facility, such as an arterial or collector road.[4]
The mainline is the controlled-access highway in a service interchange, while the crossroad is the lower-order facility that often includes at-grade intersections or roundabouts, which may pass over or under the mainline.[5]
Complete interchange
A junction where all possible movements between highways can be made from any direction.[6]
Incomplete interchange
A junction that is missing at least one movement between highways.[6]
Ramp (NA), slip road (UK), or link (Ireland)
A short section of road that allows vehicles to enter or exit a controlled-access highway.[7][8][9][10]
Ingressing traffic is entering the highway via an on-ramp or entrance ramp, while egressing traffic is exiting the highway via an off-ramp or exit ramp.[11]
Directional ramp
A ramp that curves toward the desired direction of travel; i.e., a ramp that makes a left turn exits from the left side of the roadway (a left exit).[12]
Semi-directional ramp
A ramp that exits in a direction opposite from the desired direction of travel, then turns toward the desired direction. Most left turn movements are provided by a semi-directional ramp that exits to the right, rather than exiting from the left.[12]
Weaving
An undesirable situation where traffic entering and exiting a highway must cross paths within a limited distance.[13]

History

The concept of the controlled-access highway developed in the 1920s and 1930s in Italy, Germany, the United States and Canada. Initially, these roads featured at-grade intersections along their length. Interchanges were developed to provide access between these new highways and heavily-travelled surface streets. The Bronx River Parkway was the first road to feature grade-separations.[14][15]Maryland engineer Arthur Hale filed a patent for the design of a cloverleaf interchange on May 24, 1915,[16] though the conceptual roadwork was not realised until a cloverleaf opened on December 15, 1929, in Woodbridge, New Jersey, connecting New Jersey Route 25 and Route 4 (now U.S. Route 1/9 and New Jersey Route 35). It was designed by Philadelphia engineering firm Rudolph and Delano, based on a design seen in an Argentinian magazine.[17][18][15]

System interchange

 
Comparison of traffic flows for some four-legged complete interchanges (animation)

A system interchange connects multiple controlled-access highways, involving no at-grade signalised intersections.[4]

Four-legged interchanges

Cloverleaf interchange

Main article: Cloverleaf interchange

A cloverleaf interchange is a four-legged junction where left turns across opposing traffic are handled by non-directional loop ramps.[19] It is named for its appearance from above, which resembles a four-leaf clover.[17] A cloverleaf is the absolute minimum interchange required for a four-legged system interchange. Although they were commonplace until the 1970s, most highway departments and ministries have sought to rebuild them into more efficient and safer designs.[19] The cloverleaf interchange was invented by Maryland engineer Arthur Hale, who filed a patent for its design on May 24, 1915.[16] The first one in North America opened on December 15, 1929, in Woodbridge, New Jersey, connecting New Jersey Route 25 and Route 4 (now U.S. Route 1/9 and New Jersey Route 35). It was designed by Philadelphia engineering firm Rudolph and Delano, based on a design seen in an Argentinian magazine.[17][18]

The first cloverleaf in Canada opened in 1937 at the junction of Highway 10 and what would become the Queen Elizabeth Way.[20] The first cloverleaf outside of North America opened in Stockholm on October 15, 1935. Nicknamed Slussen, it was referred to as a "traffic carousel" and was considered a revolutionary design at the time of its construction.[21]

A cloverleaf offers uninterrupted connections between two roads, but suffers from weaving issues. Along the mainline, a loop ramp introduces traffic prior to a second loop ramp providing access to the crossroad, between which ingress and egress traffic mixes. For this reason, the cloverleaf interchange has fallen out of favour in place of combination interchanges.[17] Some may be half cloverleaf containing ghost ramps which can be upgraded to full cloverleafs if the road is extended. US 70 and US 17 west of New Bern, North Carolina is an example.

Stack interchange

Main article: Stack interchange

A stack interchange is a four-way interchange whereby a semi-directional left turn and a directional right turn are both available. Usually access to both turns is provided simultaneously by a single offramp. Assuming right-handed driving, in order to cross over incoming traffic and go left, vehicles first exit onto an off-ramp from the rightmost lane. After demerging from right-turning traffic, they complete their left turn by crossing both highways on a flyover ramp or underpass. The penultimate step is a merge with the right-turn on-ramp traffic from the opposite quadrant of the interchange. Finally an onramp merges both streams of incoming traffic into the left-bound highway. As there is only one offramp and one onramp (in that respective order), stacks do not suffer from the problem of weaving, and due to the semi-directional flyover ramps and directional ramps, they are generally safe and efficient at handling high traffic volumes in all directions.

A standard stack interchange includes roads on four levels, also known as a four-level stack: including the two perpendicular highways, and one more additional level for each pair of left-turn ramps. These ramps can be stacked (cross) in various configurations above, below, or between the two interchanging highways. This makes them distinct from Turbine interchanges, where pairs of left-turn ramps are separated but at the same level. There are some stacks that could be considered five-level; however, these remain four-way interchanges, since the fifth level actually consists of dedicated ramps for HOV/bus lanes or frontage roads running through the interchange. The stack interchange between I-10 and I-405 in Los Angeles is a three-level stack, since the semi-directional ramps are spaced out far enough so they do not need to cross each other at a single point as in a conventional four-level stack.

Stacks are significantly more expensive than other four-way interchanges, due to the design of the four levels. Additionally they may suffer from objections of local residents, because of their height and high visual impact. Large stacks with multiple levels may have a complex appearance and are often colloquially described as Mixing Bowls, Mixmasters (for a Sunbeam Products brand of electric kitchen mixers), or as Spaghetti Bowls or Spaghetti Junctions (being compared to boiled spaghetti). However, they consume a significantly smaller area of land compared to a cloverleaf interchange.

Combination interchange

 
Cloverstack Interchange

A combination interchange (sometimes referred to by the portmanteau, cloverstack)[22][23] is a hybrid of other interchange designs. It uses loop ramps to serve slower or less-occupied traffic flow, and flyover ramps to serve faster and heavier traffic flows.[24][25] If local and express ways serving the same directions and each roadway is connected righthand to the interchange, extra ramps are installed. The combination interchange design is commonly used to upgrade cloverleaf interchanges to increase their capacity and eliminate weaving.[26]

Turbine interchange

 
Two-level turbine
 
Turbine-stack
hybrid
Some two-level turbines:

Some turbine-stack hybrids:

The turbine interchange is an alternative four-way directional interchange. The turbine interchange requires fewer levels (usually two or three) while retaining directional ramps throughout. It features right-exit, left-turning ramps that sweep around the center of the interchange in a clockwise spiral. A full turbine interchange features a minimum of 18 overpasses, and require more land to construct than a four-level stack interchange, however, the bridges are generally short in length. Coupled with reduced maintenance costs, a turbine interchange is a less costly alternative to a stack.[30]

Windmill interchange

 
The Vaanplein [nl] junction in Barendrecht, Netherlands was a windmill before it was renovated in 1977.
51°51′55″N 4°30′56″E / 51.8654048°N 4.5154236°E / 51.8654048; 4.5154236

A windmill interchange is similar to a turbine interchange, but it has much sharper turns, reducing its size and capacity. The interchange is named for its similar overhead appearance to the blades of a windmill.

A variation of the windmill, called the diverging windmill, increases capacity by altering the direction of traffic flow of the interchanging highways, making the connecting ramps much more direct.[31] There also is a hybrid interchange somewhat like the diverging windmill in which left turn exits merge on the left, but it differs in that the left turn exits use left directional ramps.

Braided interchange

 
A diverging interchange at I-95 and I-695 in Baltimore in 1998.

A braided or diverging interchange is a two-level, four-way interchange. An interchange is braided when at least one of the roadways reverses sides. It seeks to make left and right turns equally easy.[32] In a pure braided interchange, each roadway has one right exit, one left exit, one right on-ramp, and one left on-ramp, and both roadways are flipped.

The first pure braided interchange was built in Baltimore at Interstate 95 at Interstate 695;[33] however, the interchange was reconfigured in 2008 to a traditional stack interchange.[34]

Examples

Three-level roundabout

Main article: Roundabout interchange
 
Two level roundabout
50°33′23″N 7°14′55″E / 50.556257°N 7.248577°E / 50.556257; 7.248577
 
Three level roundabout
52°23′04″N 4°42′27″E / 52.384416°N 4.707492°E / 52.384416; 4.707492
 
Complex roundabout interchange Kleinpolderplein in Rotterdam, the Netherlands. 51°55′53″N 4°26′19″E / 51.931498°N 4.438479°E / 51.931498; 4.438479

A three-level roundabout interchange features a grade-separated roundabout which handles traffic exchanging between highways.[10] The ramps of the interchanging highways meet at a roundabout, or rotary, on a separated level above, below, or in the middle of the two highways.

Three-legged interchanges

These interchanges can also be used to make a "linking road" to the destination for a service interchange, or the creation of a new basic road as a service interchange.

Trumpet interchange

Trumpet interchanges may be used where one highway terminates at another highway, and are named as such for to their resemblance to trumpets. They are sometimes called jug handles.[35]

These interchanges are very common on toll roads, as they concentrate all entering and exiting traffic into a single stretch of roadway, where toll plazas can be installed once to handle all traffic, especially on ticket-based tollways. A double-trumpet interchange can be found where a toll road meets another toll road or a free highway. They are also useful when most traffic on the terminating highway is going in the same direction. The turn that is used less often would contain the slower loop ramp.[36]

Trumpet interchanges are often used instead of directional or semi-directional T or Y interchanges because they require less bridge construction but still eliminate weaving.[citation needed]

T and Y interchanges

 
Full Y

A full Y-interchange (also known as a directional T interchange) is typically used when a three-way interchange is required for two or three highways interchanging in semi-parallel/perpendicular directions, but it can also be used in right-angle case as well. Their connecting ramps can spur from either the right or left side of the highway, depending on the direction of travel and the angle.

Directional T interchanges use flyover/underpass ramps for both connecting and mainline segments, and they require a moderate amount of land and moderate costs since only two levels of roadway are typically used. Their name derives from their resemblance to the capital letter T, depending upon the angle from which the interchange is seen and the alignment of the roads that are interchanging. It is sometimes known as the "New England Y", as this design is often seen in the northeastern United States, particularly in Connecticut. [37]

This type of interchange features directional ramps (no loops, or weaving right to turn left) and can use multilane ramps in comparatively little space. Some designs have two ramps and the "inside" through road (on the same side as the freeway that ends) crossing each other at a three-level bridge. The directional T interchange is preferred to a trumpet interchange because a trumpet requires a loop ramp by which speeds can be reduced, but flyover ramps can handle much faster speeds. The disadvantage of the directional T is that traffic from the terminating road enters and leaves on the passing lane, so the semi-directional T interchange (see below) is preferred.

The interchange of Highway 416 and Highway 417 in Ontario, constructed in the early 1990s, is one of the few directional T interchanges, as most transportation departments had switched to the semi-directional T design.

As with a directional T interchange, a semi-directional T interchange uses flyover (overpass) or underpass ramps in all directions at a three-way interchange. However, in a semi-directional T, some of the splits and merges are switched to avoid ramps to and from the passing lane, eliminating the major disadvantage of the directional T. Semi-directional T interchanges are generally safe and efficient, though they do require more land and are costlier than trumpet interchanges.

 
Semi-directional T interchange

Semi-directional T interchanges are built as two- or three-level junctions, with three-level interchanges typically used in urban or suburban areas where land is more expensive. In a three-level semi-directional T, the two semi-directional ramps from the terminating highway cross the surviving highway at or near a single point, which requires both an overpass and underpass. In a two-level semi-directional T, the two semi-directional ramps from the terminating highway cross each other at a different point than the surviving highway, necessitating longer ramps and often one ramp having two overpasses. Highway 412 has a three-level semi-directional T at Highway 407 and a two-level semi-directional T at Highway 401.

Service interchange

Service interchanges are used between a controlled-access route and a crossroad that is not controlled-access. A full cloverleaf may be used as a system or a service interchange.[19]

Diamond interchange

Main article: Diamond interchange

A diamond interchange is an interchange involving four ramps where they enter and leave the freeway at a small angle and meet the non-freeway at almost right angles. These ramps at the non-freeway can be controlled through stop signs, traffic signals, or turn ramps.

Diamond interchanges are much more economical in use of materials and land than other interchange designs, as the junction does not normally require more than one bridge to be constructed. However, their capacity is lower than other interchanges and when traffic volumes are high they can easily become congested.

Double roundabout diamond

A double roundabout diamond interchange, also known as a dumbbell interchange or a dogbone interchange, is similar to the diamond interchange, but uses a pair of roundabouts in place of intersections to join the highway ramps with the crossroad. This typically increases the efficiency of the interchange when compared to a diamond, but is only ideal in light traffic conditions. In the dogbone variation, the roundabouts do not form a complete circle, instead having a teardrop shape, with the points facing towards the center of the interchange. Longer ramps are often required due to line-of-sight requirements at roundabouts.[38]

Partial cloverleaf interchange

Main article: Partial cloverleaf interchange

A partial cloverleaf interchange (often shortened to the portmanteau, parclo) is an interchange with loops ramps in one to three quadrants, and diamond interchange ramps in any number of quadrants. The various configurations are generally a safer modification of the cloverleaf design, due to a partial or complete reduction in weaving, but may require traffic lights on the lesser-travelled crossroad. Depending on the number of ramps used, they take up a moderate to large amount of land, and have varying capacity and efficiency.[39]

Parclo configurations are given names based on the location of and number of quadrants with ramps. The letter A denotes that, for traffic on the controlled-access highway, the loop ramps are located in advance of (or approaching) the crossroad, and thus provide an onramp to the highway. The letter B indicated that the loop ramps are beyond the crossroad, and thus provide an offramp from the highway. These letters can be used together when opposite directions of travel on the controlled-access highway are not symmetrical, thus a parclo AB features a loop ramp approaching the crossroad in one direction, and beyond the crossroad in the opposing direction, as in the example image.[40]

Diverging diamond interchange

Main article: Diverging diamond interchange

A diverging diamond interchange (DDI) or double crossover diamond interchange (DCD) is similar to a traditional diamond interchange, except the opposing lanes on the crossroad cross each other twice, once on each side of the highway. This allows all highway entrances and exits to avoid crossing the opposite direction of travel and saves one signal phase of traffic lights each.[41]

The first DDIs were constructed in the French communities of Versailles (A13 at D182), Le Perreux-sur-Marne (A4 at N486) and Seclin (A1 at D549), in the 1970s.[42] Despite the fact that such interchanges already existed, the idea for the DDI was "reinvented" around 2000, inspired by the freeway-to-freeway interchange between Interstate 95 and I-695 north of Baltimore.[43] The first DDI in the United States opened on July 7, 2009, in Springfield, Missouri, at the junction of Interstate 44 and Missouri Route 13.[44][45]

Single-point urban interchange

Main article: Single-point urban interchange
 
Single-point urban interchange along Interstate 84 in Meridian, Idaho, showing the single multi-phase traffic signal
43°35′36.5″N 116°23′37.4″W / 43.593472°N 116.393722°W / 43.593472; -116.393722

A single-point urban interchange (SPUI) or single-point diamond interchange (SPDI) is a modification of a diamond interchange in which all four ramps to and from a controlled-access highway converge at a single, three-phase traffic light in the middle of an overpass or underpass. While the compact design is safer, more efficient, and offers increased capacity—with three light phases as opposed to four in a traditional diamond, and two left turn queues on the arterial road instead of four—the significantly wider overpass or underpass structure makes them more costly than most service interchanges.[46][47] Since single-point urban interchanges can exist in rural areas, such as the interchange of U.S. Route 23 with M-59 in Michigan, and US-131 and M-179, the term single-point diamond interchange is considered the correct vernacular.[48]

Single-point interchanges were first built in the early 1970s along U.S. Route 19 in the Tampa Bay area of Florida, including the SR 694 interchange in St. Petersburg and SR 60 in Clearwater.[49]

See also

References

  1. ^ (PDF). Westlink Motorway Limited. May 2006. Archived from the original (PDF) on March 3, 2016. Retrieved July 29, 2021.
  2. ^ "Interstate System". Federal Highway Administration. February 5, 2019. Retrieved July 27, 2021.
  3. ^ Task Force on Geometric Design, 2000 (2001). "10.1 – Introduction and General Types of Interchanges". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. p. 10.1-1. ISBN 1-56051-156-7. Retrieved July 27, 2021.
  4. ^ a b c Hotchkin, Scott (20 March 2017). "The Amazing World of: Interchange Designs". Short Elliott Hendrickson Inc. Retrieved July 25, 2021.
  5. ^ Task Force on Geometric Design, 2000 (2001). "10.8.2 – Types of Separation Structures". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. p. 10-14. ISBN 1-56051-156-7. Retrieved July 30, 2021.
  6. ^ a b Epps, James W.; Stafford, Donald B. (1974). "Interchange Development Patterns on Interstate Highways in South Carolina" (PDF). 53rd Annual Meeting of Highway Research Board, Washington, DC. No. 508. Transportation Research Record. ISSN 0361-1981. Retrieved July 27, 2021.
  7. ^ Torbic, Darren J.; Lucas, Lindsay M.; Harwood, Douglas W.; et al. (2017). Design of Interchange Loop Ramps and Pavement/Shoulder Cross-Slope Breaks. National Academies of Sciences, Engineering, and Medicine. 1.1 Background. p. 18. doi:10.17226/24683. ISBN 978-0-309-45554-1.
  8. ^ "Motorways (253 to 273) – Joining the motorway (259)". The Highway Code. Government of the United Kingdom. June 27, 2014. Retrieved July 26, 2021.
  9. ^ "Motorways (253 to 273) – Leaving the motorway (272 to 273)". The Highway Code. Government of the United Kingdom. June 27, 2014. Retrieved July 26, 2021.[permanent dead link]
  10. ^ a b The Design of Major Interchanges (PDF) (Report). Transport Infrastructure Ireland. December 2020. p. 6-1. DN-GEO-03041. Retrieved August 1, 2021.
  11. ^ . Texas Department of Transportation. Archived from the original on July 18, 2021. Retrieved July 18, 2021.
  12. ^ a b Iowa Department of Transportation (September 1, 1995). "Cross Sections of One-Way Ramps and Loops" (PDF). Retrieved October 19, 2009.
  13. ^ National Cooperative Highway Research Program, Transportation Research Board (2011). "4.2.3 Weaving Segments". Guidelines for Ramp and Interchange Spacing (PDF) (Report). National Academy of Sciences. pp. 45–46. ISBN 978-0-309-15548-9. Retrieved July 27, 2021.
  14. ^ "Built to Meander, Parkway Fights to Keep Measured Pace". New York Times. June 6, 1995. Retrieved August 1, 2021.
  15. ^ a b Leisch, Joel P.; Morrall, John (2014). Evolution of Interchange Design in North America (PDF) (Report). Conference of the Transportation Association of Canada. Retrieved July 29, 2021.
  16. ^ a b "US Patent No. 1173505A". Google Patents. Retrieved July 29, 2021.
  17. ^ a b c d Martin, Hugo (April 7, 2004). . LA Times. Archived from the original on January 12, 2012. Retrieved July 29, 2021.
  18. ^ a b "New Bridge Over Raritan, 'Express Route' Opens Today". Courier-Post. Camden, New Jersey. December 15, 1929. p. 23. Retrieved July 29, 2021.
  19. ^ a b c Zhong, Hantao (2012). Free-flow Parclo Interchange vs. the Cloverleaf Interchange with C-D Roads and the All-Directional Four-level Interchange: A Comparison of Geometrics, Construction Cost, and Right of Way Requirements (PDF) (Thesis). Raleigh, North Carolina: North Carolina State University. Retrieved July 31, 2021.
  20. ^ Shragge, John; Bagnato, Sharon (1984). From Footpaths to Freeways. Ontario Ministry of Transportation and Communications, Historical Committee. pp. 79–81. ISBN 0-7743-9388-2.
  21. ^ Rundquist, Solveig (June 17, 2014). "The octopus that could save Slussen". Sweden: The Local. Retrieved July 19, 2021.
  22. ^ "Bureau of Environment Conference Report: NHDOT Monthly Natural Resource Agency Coordination Meeting" (PDF). New Hampshire Department of Transportation. August 16, 2017. Retrieved August 5, 2021.
  23. ^ McDaniel, Dana L. (February 5, 2015). "Ordinance No. 12-15" (PDF). City of Dublin, Ohio. Retrieved August 5, 2021.
  24. ^ Task Force on Geometric Design, 2000 (2001). "10 – Grade Separations and Interchanges". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. pp. 803–805. ISBN 1-56051-156-7. Retrieved July 10, 2021.
  25. ^ Publication 13M – Design Manual, Part 2 Highway Design, Chapter 4 (PDF) (6 ed.). Pennsylvania Department of Transportation. April 2021. p. 4-4. Retrieved July 10, 2021.
  26. ^ Task Force on Geometric Design, 2000 (2001). "10 – Grade Separations and Interchanges". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. pp. 10-72–10-76. ISBN 1-56051-156-7. Retrieved August 3, 2021.
  27. ^ "I-94 East Metro Interchange Study". Minnesota Department of Transportation. Retrieved July 13, 2021 – via ArcGIS.
  28. ^ "I-485/I-85 Turbine Interchange Design-Build". STV Inc. Retrieved July 13, 2021.
  29. ^ Andrew, Peter (July 22, 2015). "The art of the interchange". Politico. Retrieved July 13, 2021.
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  33. ^ Manaugh, Geoff (2005-12-29). "The knot driver". from the original on 2022-05-03. Retrieved 2022-05-03.
  34. ^ Lookingbill, Amy P. "Construction still rolling along I-95 to prepare for Express Toll Lanes". The Avenue News. Retrieved 2022-05-03.
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  37. ^ Milano, Lou. "CT Has an Absurd Number of Left Exits, the Most in New England by far". I95 Rock.
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  39. ^ Task Force on Geometric Design (2000). "10.9.3.6.1 – Partial Cloverleaf Ramp Arrangements". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. pp. 10-60–10-63. ISBN 1-56051-156-7. Retrieved July 27, 2021.
  40. ^ "10.2.10 Partial Cloverleafs". South Carolina Roadway Design Manual (PDF) (Report). South Carolina Department of Transportation. February 2021. pp. 10.2-11–10.2-12. Retrieved July 27, 2021.
  41. ^ Hughes, Warren; Jagannathan, Ram (October 2009). "Double Crossover Diamond Interchange". Federal Highway Administration. FHWA-HRT-09-054. Retrieved July 30, 2021.
  42. ^ Staff (June 13, 2013). . Virginia Department of Transportation. Archived from the original on November 27, 2013. Retrieved July 30, 2021.
  43. ^ Chlewicki, Gilbert (2003). "New Interchange and Intersection Designs: The Synchronized Split-Phasing Intersection and the Diverging Diamond Interchange" (PDF). Archived from the original (PDF) on October 20, 2011. Retrieved October 20, 2009.
  44. ^ "Missouri Department of Transportation" (PDF).
  45. ^ Staff (June 2011). . Missouri Department of Transportation. Archived from the original on June 7, 2011. Retrieved October 3, 2015.
  46. ^ "Innovative Intersections and Interchanges". Virginia Department of Transportation. November 17, 2020. Retrieved July 27, 2021.
  47. ^ "Single-Point Urban Interchanges". Missouri Department of Transportation. Retrieved July 27, 2021.
  48. ^ Task Force on Geometric Design, 2000 (2001). "10.9.3.4 – Single-Point Diamond Interchanges". A Policy on Geometric Design of Highways and Streets (PDF). AASHTO. p. 10-48. ISBN 1-56051-156-7. Retrieved July 27, 2021.
  49. ^ Bonneson, James A.; Messer, Carroll J. (March 1989). National Survey of Single-Point Urban Interchanges (Report no. FHWA/TX-88/1148-1) (PDF) (Report). Federal Highway Administration. Retrieved July 27, 2021.

External links

 
Wikimedia Commons has media related to Interchanges.
  •  – Part of the publication by the Turner-Fairbank Highway Research Center branch of the U.S. Federal Highway Administration
  • Kurumi.com U.S. interchanges directory
  • (in German)
  • How New Jersey Saved Civilization: The first cloverleaf interchange

March 28, 2023
interchange, road, offramp, redirects, here, other, uses, offramp, disambiguation, slip, road, limited, access, ramp, redirect, here, turn, lane, intersection, slip, lane, field, road, transport, interchange, american, english, grade, separated, junction, brit. Offramp redirects here For other uses see Offramp disambiguation Slip road and Limited access ramp redirect here For the turn lane at an intersection see Slip lane In the field of road transport an interchange American English or a grade separated junction British English is a road junction that uses grade separations to allow for the movement of traffic between two or more roadways or highways using a system of interconnecting roadways to permit traffic on at least one of the routes to pass through the junction without interruption from 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 freeway or motorway or a limited access divided highway expressway though they are sometimes used at junctions between surface streets The High Five in Dallas Texas This is a complicated five level stack interchange due to the proximity of frontage roads and segregated high occupancy vehicle lanes This hybrid design is based on parts of a four level stack for highways with a three level diamond interchange to handle the frontage roads 32 55 27 2 N 96 45 50 0 W 32 924222 N 96 763889 W 32 924222 96 763889 An aerial view of the Lakalaiva interchange in the Tampere Ring Road between the Highway 3 E12 and Highway 9 E63 near city of Tampere 61 27 46 N 23 46 10 E 61 46278 N 23 76944 E 61 46278 23 76944 Contents 1 Terminology 2 History 3 System interchange 3 1 Four legged interchanges 3 1 1 Cloverleaf interchange 3 1 2 Stack interchange 3 1 3 Combination interchange 3 1 4 Turbine interchange 3 1 5 Windmill interchange 3 1 6 Braided interchange 3 1 7 Three level roundabout 3 2 Three legged interchanges 3 2 1 Trumpet interchange 3 2 2 T and Y interchanges 4 Service interchange 4 1 Diamond interchange 4 2 Partial cloverleaf interchange 4 3 Diverging diamond interchange 4 4 Single point urban interchange 5 See also 6 References 7 External linksTerminology Edit An interchange between the M0 and M4 motorways outside Budapest showcases directional semi directional and loop ramps 47 24 18 N 19 18 55 E 47 40500 N 19 31528 E 47 40500 19 31528 The Light Horse Interchange in Sydney the largest in Australia 1 33 47 53 S 150 51 15 E 33 79806 S 150 85417 E 33 79806 150 85417 Note The descriptions of interchanges apply to countries where vehicles drive on the right side of the road For left side driving the layout of junctions is mirrored Both North American NA and British UK terminology is included Freeway junction highway interchange NA or motorway junction UK A type of road junction linking one controlled access highway freeway or motorway facility to another to other roads or to a rest area or motorway service area Junctions and interchanges are often but not always numbered either sequentially or by distance from one terminus of the route the beginning of the route 2 The American Association of State Highway and Transportation Officials AASHTO defines an interchange as a system of interconnecting roadways in conjunction with one or more grade separations that provides for the movement of traffic between two or more roadways or highways on different levels 3 System interchange A junction that connects multiple controlled access highways 4 Service interchange A junction that connects a controlled access facility to a lower order facility such as an arterial or collector road 4 The mainline is the controlled access highway in a service interchange while the crossroad is the lower order facility that often includes at grade intersections or roundabouts which may pass over or under the mainline 5 Complete interchange A junction where all possible movements between highways can be made from any direction 6 Incomplete interchange A junction that is missing at least one movement between highways 6 Ramp NA slip road UK or link Ireland A short section of road that allows vehicles to enter or exit a controlled access highway 7 8 9 10 Ingressing traffic is entering the highway via an on ramp or entrance ramp while egressing traffic is exiting the highway via an off ramp or exit ramp 11 Directional ramp A ramp that curves toward the desired direction of travel i e a ramp that makes a left turn exits from the left side of the roadway a left exit 12 Semi directional ramp A ramp that exits in a direction opposite from the desired direction of travel then turns toward the desired direction Most left turn movements are provided by a semi directional ramp that exits to the right rather than exiting from the left 12 Weaving An undesirable situation where traffic entering and exiting a highway must cross paths within a limited distance 13 History EditThe concept of the controlled access highway developed in the 1920s and 1930s in Italy Germany the United States and Canada Initially these roads featured at grade intersections along their length Interchanges were developed to provide access between these new highways and heavily travelled surface streets The Bronx River Parkway was the first road to feature grade separations 14 15 Maryland engineer Arthur Hale filed a patent for the design of a cloverleaf interchange on May 24 1915 16 though the conceptual roadwork was not realised until a cloverleaf opened on December 15 1929 in Woodbridge New Jersey connecting New Jersey Route 25 and Route 4 now U S Route 1 9 and New Jersey Route 35 It was designed by Philadelphia engineering firm Rudolph and Delano based on a design seen in an Argentinian magazine 17 18 15 System interchange Edit Comparison of traffic flows for some four legged complete interchanges animation A system interchange connects multiple controlled access highways involving no at grade signalised intersections 4 Four legged interchanges Edit Cloverleaf interchange Edit Main article Cloverleaf interchange A full cloverleaf interchange between APD 40 and U S Route 64 near Cleveland Tennessee 35 08 59 4 N 84 50 52 3 W 35 149833 N 84 847861 W 35 149833 84 847861 A cloverleaf interchange is a four legged junction where left turns across opposing traffic are handled by non directional loop ramps 19 It is named for its appearance from above which resembles a four leaf clover 17 A cloverleaf is the absolute minimum interchange required for a four legged system interchange Although they were commonplace until the 1970s most highway departments and ministries have sought to rebuild them into more efficient and safer designs 19 The cloverleaf interchange was invented by Maryland engineer Arthur Hale who filed a patent for its design on May 24 1915 16 The first one in North America opened on December 15 1929 in Woodbridge New Jersey connecting New Jersey Route 25 and Route 4 now U S Route 1 9 and New Jersey Route 35 It was designed by Philadelphia engineering firm Rudolph and Delano based on a design seen in an Argentinian magazine 17 18 The first cloverleaf in Canada opened in 1937 at the junction of Highway 10 and what would become the Queen Elizabeth Way 20 The first cloverleaf outside of North America opened in Stockholm on October 15 1935 Nicknamed Slussen it was referred to as a traffic carousel and was considered a revolutionary design at the time of its construction 21 A cloverleaf offers uninterrupted connections between two roads but suffers from weaving issues Along the mainline a loop ramp introduces traffic prior to a second loop ramp providing access to the crossroad between which ingress and egress traffic mixes For this reason the cloverleaf interchange has fallen out of favour in place of combination interchanges 17 Some may be half cloverleaf containing ghost ramps which can be upgraded to full cloverleafs if the road is extended US 70 and US 17 west of New Bern North Carolina is an example Stack interchange Edit This section does not cite any sources Please help improve this section by adding citations to reliable sources Unsourced material may be challenged and removed June 2022 Learn how and when to remove this template message Main article Stack interchange A multi level stack interchange in Jing an Shanghai China 31 13 27 7 N 121 28 09 0 E 31 224361 N 121 469167 E 31 224361 121 469167 A stack interchange is a four way interchange whereby a semi directional left turn and a directional right turn are both available Usually access to both turns is provided simultaneously by a single offramp Assuming right handed driving in order to cross over incoming traffic and go left vehicles first exit onto an off ramp from the rightmost lane After demerging from right turning traffic they complete their left turn by crossing both highways on a flyover ramp or underpass The penultimate step is a merge with the right turn on ramp traffic from the opposite quadrant of the interchange Finally an onramp merges both streams of incoming traffic into the left bound highway As there is only one offramp and one onramp in that respective order stacks do not suffer from the problem of weaving and due to the semi directional flyover ramps and directional ramps they are generally safe and efficient at handling high traffic volumes in all directions A standard stack interchange includes roads on four levels also known as a four level stack including the two perpendicular highways and one more additional level for each pair of left turn ramps These ramps can be stacked cross in various configurations above below or between the two interchanging highways This makes them distinct from Turbine interchanges where pairs of left turn ramps are separated but at the same level There are some stacks that could be considered five level however these remain four way interchanges since the fifth level actually consists of dedicated ramps for HOV bus lanes or frontage roads running through the interchange The stack interchange between I 10 and I 405 in Los Angeles is a three level stack since the semi directional ramps are spaced out far enough so they do not need to cross each other at a single point as in a conventional four level stack Stacks are significantly more expensive than other four way interchanges due to the design of the four levels Additionally they may suffer from objections of local residents because of their height and high visual impact Large stacks with multiple levels may have a complex appearance and are often colloquially described as Mixing Bowls Mixmasters for a Sunbeam Products brand of electric kitchen mixers or as Spaghetti Bowls or Spaghetti Junctions being compared to boiled spaghetti However they consume a significantly smaller area of land compared to a cloverleaf interchange Combination interchange Edit Cloverstack Interchange A combination interchange sometimes referred to by the portmanteau cloverstack 22 23 is a hybrid of other interchange designs It uses loop ramps to serve slower or less occupied traffic flow and flyover ramps to serve faster and heavier traffic flows 24 25 If local and express ways serving the same directions and each roadway is connected righthand to the interchange extra ramps are installed The combination interchange design is commonly used to upgrade cloverleaf interchanges to increase their capacity and eliminate weaving 26 Turbine interchange Edit Two level turbine Turbine stackhybridSome two level turbines Dubai UAE citation needed 25 03 22 N 55 14 57 E 25 0561 N 55 2493 E 25 0561 55 2493 Jacksonville Florida US 27 30 15 11 N 81 30 59 W 30 2531 N 81 5163 W 30 2531 81 5163 Charlotte North Carolina US 28 35 20 54 N 80 44 01 W 35 3482 N 80 7335 W 35 3482 80 7335 Amarillo Texas US 29 35 11 34 N 101 50 14 W 35 1929 N 101 8371 W 35 1929 101 8371Some turbine stack hybrids Warren Michigan US 42 29 16 N 83 02 45 W 42 4879 N 83 0457 W 42 4879 83 0457 Town and Country Missouri US 38 38 19 N 90 26 59 W 38 6386 N 90 4497 W 38 6386 90 4497 A turbine interchange between A201 and the Brussels Ring R0 in Brussels50 53 30 1 N 4 27 15 3 E 50 891694 N 4 454250 E 50 891694 4 454250 The turbine interchange is an alternative four way directional interchange The turbine interchange requires fewer levels usually two or three while retaining directional ramps throughout It features right exit left turning ramps that sweep around the center of the interchange in a clockwise spiral A full turbine interchange features a minimum of 18 overpasses and require more land to construct than a four level stack interchange however the bridges are generally short in length Coupled with reduced maintenance costs a turbine interchange is a less costly alternative to a stack 30 Windmill interchange Edit This section possibly contains original research Please improve it by verifying the claims made and adding inline citations Statements consisting only of original research should be removed February 2022 Learn how and when to remove this template message The Vaanplein nl junction in Barendrecht Netherlands was a windmill before it was renovated in 1977 51 51 55 N 4 30 56 E 51 8654048 N 4 5154236 E 51 8654048 4 5154236 A windmill interchange is similar to a turbine interchange but it has much sharper turns reducing its size and capacity The interchange is named for its similar overhead appearance to the blades of a windmill A variation of the windmill called the diverging windmill increases capacity by altering the direction of traffic flow of the interchanging highways making the connecting ramps much more direct 31 There also is a hybrid interchange somewhat like the diverging windmill in which left turn exits merge on the left but it differs in that the left turn exits use left directional ramps Braided interchange Edit A diverging interchange at I 95 and I 695 in Baltimore in 1998 A braided or diverging interchange is a two level four way interchange An interchange is braided when at least one of the roadways reverses sides It seeks to make left and right turns equally easy 32 In a pure braided interchange each roadway has one right exit one left exit one right on ramp and one left on ramp and both roadways are flipped The first pure braided interchange was built in Baltimore at Interstate 95 at Interstate 695 33 however the interchange was reconfigured in 2008 to a traditional stack interchange 34 ExamplesInterstate 65 and Interstate 20 Interstate 59 in Birmingham Alabama 33 31 17 N 86 49 35 W 33 521414 N 86 826513 W 33 521414 86 826513 Interstate 196 and U S Route 131 in Grand Rapids Michigan 42 58 21 N 85 40 40 W 42 972487 N 85 677781 W 42 972487 85 677781 Interstate 77 and Interstate 85 in Charlotte North Carolina 35 16 23 N 80 50 44 W 35 272967 N 80 845550 W 35 272967 80 845550 South of Riyadh specify 24 37 54 N 46 48 12 E 24 631542 N 46 803334 E 24 631542 46 803334 Three level roundabout Edit Main article Roundabout interchange Two level roundabout50 33 23 N 7 14 55 E 50 556257 N 7 248577 E 50 556257 7 248577 Three level roundabout52 23 04 N 4 42 27 E 52 384416 N 4 707492 E 52 384416 4 707492 Complex roundabout interchange Kleinpolderplein in Rotterdam the Netherlands 51 55 53 N 4 26 19 E 51 931498 N 4 438479 E 51 931498 4 438479 A three level roundabout interchange features a grade separated roundabout which handles traffic exchanging between highways 10 The ramps of the interchanging highways meet at a roundabout or rotary on a separated level above below or in the middle of the two highways Three legged interchanges Edit This section possibly contains original research Please improve it by verifying the claims made and adding inline citations Statements consisting only of original research should be removed July 2021 Learn how and when to remove this template message These interchanges can also be used to make a linking road to the destination for a service interchange or the creation of a new basic road as a service interchange Trumpet interchange Edit A trumpet interchange on the Sir John A Macdonald Parkway in Ottawa45 24 41 N 75 44 7 W 45 41139 N 75 73528 W 45 41139 75 73528 Trumpet interchanges may be used where one highway terminates at another highway and are named as such for to their resemblance to trumpets They are sometimes called jug handles 35 These interchanges are very common on toll roads as they concentrate all entering and exiting traffic into a single stretch of roadway where toll plazas can be installed once to handle all traffic especially on ticket based tollways A double trumpet interchange can be found where a toll road meets another toll road or a free highway They are also useful when most traffic on the terminating highway is going in the same direction The turn that is used less often would contain the slower loop ramp 36 Trumpet interchanges are often used instead of directional or semi directional T or Y interchanges because they require less bridge construction but still eliminate weaving citation needed T and Y interchanges Edit Full Y Complex T interchange of SR 85 and SR 87 in San Jose California 37 15 21 N 121 51 32 W 37 255721 N 121 858878 W 37 255721 121 858878 A full Y interchange also known as a directional T interchange is typically used when a three way interchange is required for two or three highways interchanging in semi parallel perpendicular directions but it can also be used in right angle case as well Their connecting ramps can spur from either the right or left side of the highway depending on the direction of travel and the angle Directional T interchanges use flyover underpass ramps for both connecting and mainline segments and they require a moderate amount of land and moderate costs since only two levels of roadway are typically used Their name derives from their resemblance to the capital letter T depending upon the angle from which the interchange is seen and the alignment of the roads that are interchanging It is sometimes known as the New England Y as this design is often seen in the northeastern United States particularly in Connecticut 37 This type of interchange features directional ramps no loops or weaving right to turn left and can use multilane ramps in comparatively little space Some designs have two ramps and the inside through road on the same side as the freeway that ends crossing each other at a three level bridge The directional T interchange is preferred to a trumpet interchange because a trumpet requires a loop ramp by which speeds can be reduced but flyover ramps can handle much faster speeds The disadvantage of the directional T is that traffic from the terminating road enters and leaves on the passing lane so the semi directional T interchange see below is preferred The interchange of Highway 416 and Highway 417 in Ontario constructed in the early 1990s is one of the few directional T interchanges as most transportation departments had switched to the semi directional T design Two level semi directional T interchange in Orbe Switzerland 46 43 42 N 6 34 11 E 46 72836 N 6 569738 E 46 72836 6 569738 As with a directional T interchange a semi directional T interchange uses flyover overpass or underpass ramps in all directions at a three way interchange However in a semi directional T some of the splits and merges are switched to avoid ramps to and from the passing lane eliminating the major disadvantage of the directional T Semi directional T interchanges are generally safe and efficient though they do require more land and are costlier than trumpet interchanges Semi directional T interchange Semi directional T interchanges are built as two or three level junctions with three level interchanges typically used in urban or suburban areas where land is more expensive In a three level semi directional T the two semi directional ramps from the terminating highway cross the surviving highway at or near a single point which requires both an overpass and underpass In a two level semi directional T the two semi directional ramps from the terminating highway cross each other at a different point than the surviving highway necessitating longer ramps and often one ramp having two overpasses Highway 412 has a three level semi directional T at Highway 407 and a two level semi directional T at Highway 401 Half cloverSamples 38 00 49 N 97 58 05 W 38 013535 N 97 967935 W 38 013535 97 967935 51 314277 N 7 266172 E 3 4 volley T boneSamples 39 55 46 N 86 16 00 W 39 929458 N 86 266563 W 39 929458 86 266563 36 06 38 N 94 10 20 W 36 110434 N 94 172332 W 36 110434 94 172332 Three way roundaboutSamples 48 07 12 10 N 7 22 02 65 E 48 1200278 N 7 3674028 E 48 1200278 7 3674028 37 38 40 74 N 126 45 00 11 E 37 6446500 N 126 7500306 E 37 6446500 126 7500306 Roundabout TSamples 38 59 38 N 95 13 46 W 38 993949 N 95 229507 W 38 993949 95 229507 34 27 22 N 118 36 57 W 34 455985 N 118 615761 W 34 455985 118 615761 32 36 06 N 80 45 34 W 32 601667 N 80 759485 W 32 601667 80 759485 Service interchange EditService interchanges are used between a controlled access route and a crossroad that is not controlled access A full cloverleaf may be used as a system or a service interchange 19 Diamond interchange Edit Main article Diamond interchange A typical diamond interchange located at the junction of Florida State Road 435 and the Spessard L Holland East West Expressway28 32 56 3 N 81 27 25 9 W 28 548972 N 81 457194 W 28 548972 81 457194 A diamond interchange is an interchange involving four ramps where they enter and leave the freeway at a small angle and meet the non freeway at almost right angles These ramps at the non freeway can be controlled through stop signs traffic signals or turn ramps Diamond interchanges are much more economical in use of materials and land than other interchange designs as the junction does not normally require more than one bridge to be constructed However their capacity is lower than other interchanges and when traffic volumes are high they can easily become congested Double roundabout diamond A dumbbell interchange along Ontario Highway 401 in Clarington43 53 3 N 78 43 20 W 43 88417 N 78 72222 W 43 88417 78 72222 A double roundabout diamond interchange also known as a dumbbell interchange or a dogbone interchange is similar to the diamond interchange but uses a pair of roundabouts in place of intersections to join the highway ramps with the crossroad This typically increases the efficiency of the interchange when compared to a diamond but is only ideal in light traffic conditions In the dogbone variation the roundabouts do not form a complete circle instead having a teardrop shape with the points facing towards the center of the interchange Longer ramps are often required due to line of sight requirements at roundabouts 38 Partial cloverleaf interchange Edit Main article Partial cloverleaf interchange A parclo A4 interchange along Highway 407 in Ontario Canada43 34 17 8 N 79 47 23 6 W 43 571611 N 79 789889 W 43 571611 79 789889 A parclo AB2 or folded diamond interchange along Bundesautobahn 7 in Germany47 38 28 68 N 10 31 40 08 E 47 6413000 N 10 5278000 E 47 6413000 10 5278000 A partial cloverleaf interchange often shortened to the portmanteau parclo is an interchange with loops ramps in one to three quadrants and diamond interchange ramps in any number of quadrants The various configurations are generally a safer modification of the cloverleaf design due to a partial or complete reduction in weaving but may require traffic lights on the lesser travelled crossroad Depending on the number of ramps used they take up a moderate to large amount of land and have varying capacity and efficiency 39 Parclo configurations are given names based on the location of and number of quadrants with ramps The letter A denotes that for traffic on the controlled access highway the loop ramps are located in advance of or approaching the crossroad and thus provide an onramp to the highway The letter B indicated that the loop ramps are beyond the crossroad and thus provide an offramp from the highway These letters can be used together when opposite directions of travel on the controlled access highway are not symmetrical thus a parclo AB features a loop ramp approaching the crossroad in one direction and beyond the crossroad in the opposing direction as in the example image 40 Diverging diamond interchange Edit Main article Diverging diamond interchange A diverging diamond at Interstate 285 and Camp Creek Parkway near Atlanta33 39 23 5 N 84 29 51 5 W 33 656528 N 84 497639 W 33 656528 84 497639 A diverging diamond interchange DDI or double crossover diamond interchange DCD is similar to a traditional diamond interchange except the opposing lanes on the crossroad cross each other twice once on each side of the highway This allows all highway entrances and exits to avoid crossing the opposite direction of travel and saves one signal phase of traffic lights each 41 The first DDIs were constructed in the French communities of Versailles A13 at D182 Le Perreux sur Marne A4 at N486 and Seclin A1 at D549 in the 1970s 42 Despite the fact that such interchanges already existed the idea for the DDI was reinvented around 2000 inspired by the freeway to freeway interchange between Interstate 95 and I 695 north of Baltimore 43 The first DDI in the United States opened on July 7 2009 in Springfield Missouri at the junction of Interstate 44 and Missouri Route 13 44 45 Single point urban interchange Edit Main article Single point urban interchange Single point urban interchange along Interstate 84 in Meridian Idaho showing the single multi phase traffic signal43 35 36 5 N 116 23 37 4 W 43 593472 N 116 393722 W 43 593472 116 393722 A single point urban interchange SPUI or single point diamond interchange SPDI is a modification of a diamond interchange in which all four ramps to and from a controlled access highway converge at a single three phase traffic light in the middle of an overpass or underpass While the compact design is safer more efficient and offers increased capacity with three light phases as opposed to four in a traditional diamond and two left turn queues on the arterial road instead of four the significantly wider overpass or underpass structure makes them more costly than most service interchanges 46 47 Since single point urban interchanges can exist in rural areas such as the interchange of U S Route 23 with M 59 in Michigan and US 131 and M 179 the term single point diamond interchange is considered the correct vernacular 48 Single point interchanges were first built in the early 1970s along U S Route 19 in the Tampa Bay area of Florida including the SR 694 interchange in St Petersburg and SR 60 in Clearwater 49 See also EditFree flow interchange Grade separation Intersection road Junction traffic Unused highway Ramp meter RoundaboutReferences Edit Fact Sheet Light Horse Interchange Westlink M7 M4 Motorway Interchange PDF Westlink Motorway Limited May 2006 Archived from the original PDF on March 3 2016 Retrieved July 29 2021 Interstate System Federal Highway Administration February 5 2019 Retrieved July 27 2021 Task Force on Geometric Design 2000 2001 10 1 Introduction and General Types of Interchanges A Policy on Geometric Design of Highways and Streets PDF AASHTO p 10 1 1 ISBN 1 56051 156 7 Retrieved July 27 2021 a b c Hotchkin Scott 20 March 2017 The Amazing World of Interchange Designs Short Elliott Hendrickson Inc Retrieved July 25 2021 Task Force on Geometric Design 2000 2001 10 8 2 Types of Separation Structures A Policy on Geometric Design of Highways and Streets PDF AASHTO p 10 14 ISBN 1 56051 156 7 Retrieved July 30 2021 a b Epps James W Stafford Donald B 1974 Interchange Development Patterns on Interstate Highways in South Carolina PDF 53rd Annual Meeting of Highway Research Board Washington DC No 508 Transportation Research Record ISSN 0361 1981 Retrieved July 27 2021 Torbic Darren J Lucas Lindsay M Harwood Douglas W et al 2017 Design of Interchange Loop Ramps and Pavement Shoulder Cross Slope Breaks National Academies of Sciences Engineering and Medicine 1 1 Background p 18 doi 10 17226 24683 ISBN 978 0 309 45554 1 Motorways 253 to 273 Joining the motorway 259 The Highway Code Government of the United Kingdom June 27 2014 Retrieved July 26 2021 Motorways 253 to 273 Leaving the motorway 272 to 273 The Highway Code Government of the United Kingdom June 27 2014 Retrieved July 26 2021 permanent dead link a b The Design of Major Interchanges PDF Report Transport Infrastructure Ireland December 2020 p 6 1 DN GEO 03041 Retrieved August 1 2021 Ingress Egress Texas Department of Transportation Archived from the original on July 18 2021 Retrieved July 18 2021 a b Iowa Department of Transportation September 1 1995 Cross Sections of One Way Ramps and Loops PDF Retrieved October 19 2009 National Cooperative Highway Research Program Transportation Research Board 2011 4 2 3 Weaving Segments Guidelines for Ramp and Interchange Spacing PDF Report National Academy of Sciences pp 45 46 ISBN 978 0 309 15548 9 Retrieved July 27 2021 Built to Meander Parkway Fights to Keep Measured Pace New York Times June 6 1995 Retrieved August 1 2021 a b Leisch Joel P Morrall John 2014 Evolution of Interchange Design in North America PDF Report Conference of the Transportation Association of Canada Retrieved July 29 2021 a b US Patent No 1173505A Google Patents Retrieved July 29 2021 a b c d Martin Hugo April 7 2004 A Major Lane Change LA Times Archived from the original on January 12 2012 Retrieved July 29 2021 a b New Bridge Over Raritan Express Route Opens Today Courier Post Camden New Jersey December 15 1929 p 23 Retrieved July 29 2021 a b c Zhong Hantao 2012 Free flow Parclo Interchange vs the Cloverleaf Interchange with C D Roads and the All Directional Four level Interchange A Comparison of Geometrics Construction Cost and Right of Way Requirements PDF Thesis Raleigh North Carolina North Carolina State University Retrieved July 31 2021 Shragge John Bagnato Sharon 1984 From Footpaths to Freeways Ontario Ministry of Transportation and Communications Historical Committee pp 79 81 ISBN 0 7743 9388 2 Rundquist Solveig June 17 2014 The octopus that could save Slussen Sweden The Local Retrieved July 19 2021 Bureau of Environment Conference Report NHDOT Monthly Natural Resource Agency Coordination Meeting PDF New Hampshire Department of Transportation August 16 2017 Retrieved August 5 2021 McDaniel Dana L February 5 2015 Ordinance No 12 15 PDF City of Dublin Ohio Retrieved August 5 2021 Task Force on Geometric Design 2000 2001 10 Grade Separations and Interchanges A Policy on Geometric Design of Highways and Streets PDF AASHTO pp 803 805 ISBN 1 56051 156 7 Retrieved July 10 2021 Publication 13M Design Manual Part 2 Highway Design Chapter 4 PDF 6 ed Pennsylvania Department of Transportation April 2021 p 4 4 Retrieved July 10 2021 Task Force on Geometric Design 2000 2001 10 Grade Separations and Interchanges A Policy on Geometric Design of Highways and Streets PDF AASHTO pp 10 72 10 76 ISBN 1 56051 156 7 Retrieved August 3 2021 I 94 East Metro Interchange Study Minnesota Department of Transportation Retrieved July 13 2021 via ArcGIS I 485 I 85 Turbine Interchange Design Build STV Inc Retrieved July 13 2021 Andrew Peter July 22 2015 The art of the interchange Politico Retrieved July 13 2021 Parsons Jim May 23 2012 Rare Turbine Design for Charlotte s I 85 485 Interchange ENR Southeast Retrieved July 13 2021 I 40 AT I 440 US 1 US 64 Interchange Feasibility Study Prepared for North Carolina Capital Area Metropolitan Planning Organization PDF Parsons Brinckerhoff August 2015 Retrieved January 5 2022 Dror Bar Natan s Image Gallery Knotted Objects Baltimore Interchange www math toronto edu Retrieved 2022 05 02 Manaugh Geoff 2005 12 29 The knot driver Archived from the original on 2022 05 03 Retrieved 2022 05 03 Lookingbill Amy P Construction still rolling along I 95 to prepare for Express Toll Lanes The Avenue News Retrieved 2022 05 03 48 PDF 2013 Design Manual Report Indiana Department of Transportation 2013 p 69 Retrieved August 3 2021 Task Force on Geometric Design 2000 2001 10 Grade Separations and Interchanges A Policy on Geometric Design of Highways and Streets PDF AASHTO p 10 32 ISBN 1 56051 156 7 Retrieved August 3 2021 Milano Lou CT Has an Absurd Number of Left Exits the Most in New England by far I95 Rock 10 2 7 Double Roundabout Diamond South Carolina Roadway Design Manual PDF Report South Carolina Department of Transportation February 2021 pp 10 2 7 10 2 8 Retrieved July 30 2021 Task Force on Geometric Design 2000 10 9 3 6 1 Partial Cloverleaf Ramp Arrangements A Policy on Geometric Design of Highways and Streets PDF AASHTO pp 10 60 10 63 ISBN 1 56051 156 7 Retrieved July 27 2021 10 2 10 Partial Cloverleafs South Carolina Roadway Design Manual PDF Report South Carolina Department of Transportation February 2021 pp 10 2 11 10 2 12 Retrieved July 27 2021 Hughes Warren Jagannathan Ram October 2009 Double Crossover Diamond Interchange Federal Highway Administration FHWA HRT 09 054 Retrieved July 30 2021 Staff June 13 2013 I 64 Interchange at Route 15 Zion Crossroads Virginia Department of Transportation Archived from the original on November 27 2013 Retrieved July 30 2021 Chlewicki Gilbert 2003 New Interchange and Intersection Designs The Synchronized Split Phasing Intersection and the Diverging Diamond Interchange PDF Archived from the original PDF on October 20 2011 Retrieved October 20 2009 Missouri Department of Transportation PDF Staff June 2011 I 44 Route 13 Interchange Reconstruction Diverging Diamond Design Missouri Department of Transportation Archived from the original on June 7 2011 Retrieved October 3 2015 Innovative Intersections and Interchanges Virginia Department of Transportation November 17 2020 Retrieved July 27 2021 Single Point Urban Interchanges Missouri Department of Transportation Retrieved July 27 2021 Task Force on Geometric Design 2000 2001 10 9 3 4 Single Point Diamond Interchanges A Policy on Geometric Design of Highways and Streets PDF AASHTO p 10 48 ISBN 1 56051 156 7 Retrieved July 27 2021 Bonneson James A Messer Carroll J March 1989 National Survey of Single Point Urban Interchanges Report no FHWA TX 88 1148 1 PDF Report Federal Highway Administration Retrieved July 27 2021 External links Edit Wikimedia Commons has media related to Interchanges Glossary Part of the publication Highway Design Handbook for Older Drivers and Pedestrians by the Turner Fairbank Highway Research Center branch of the U S Federal Highway Administration Kurumi com U S interchanges directory Detailed history of interchanges with diagrams in German How New Jersey Saved Civilization The first cloverleaf interchange Retrieved from https en wikipedia org w index php title Interchange road amp oldid 1146480661, wikipedia, wiki, book, books, library,

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