Misplaced Pages

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94-454: Route 10 begins at an incomplete interchange with Route 12 (Park Avenue) on the Cranston - Providence border. The bridge that carries Route 12 over Route 10 has enough space for a four-lane freeway underneath, but only the ramp from Route 12 east to Route 10 north passes under it. Until around 2000, the ramp from Route 10 south to Route 12 east instead passed under the bridge; that movement

188-735: A four-leaf clover . A cloverleaf is the 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. The cloverleaf interchange was invented by Maryland engineer Arthur Hale, who filed a patent for its design on May   24, 1915. 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

282-407: 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. 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

376-407: 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. 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

470-399: 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. A combination interchange (sometimes referred to by

564-399: 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. A combination interchange (sometimes referred to by

658-435: A design seen in an Argentinian magazine. A system interchange connects multiple controlled-access highways, involving no at-grade signalised intersections. A cloverleaf interchange is a four-legged junction where left turns across opposing traffic are handled by non-directional loop ramps. It is named for its appearance from above, which resembles a four-leaf clover . A cloverleaf is the minimum interchange required for

752-475: 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

846-475: 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

940-412: 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

1034-412: 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

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1128-537: 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. The cloverleaf interchange was invented by Maryland engineer Arthur Hale, who filed a patent for its design on May   24, 1915. 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

1222-507: A full interchange, sometimes known as the "Friendly Interchange" for the community of Quakers it partially destroyed. It then heads northwest, crossing under Pontiac Avenue and then junctioning Route 2 (Reservoir Avenue) just after crossing back into Providence. After the Route 2 interchange, Route 10 again crosses back into Cranston, running west of the parallel Niantic Avenue, which is on the city line. The final crossing, back into Providence,

1316-667: 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. 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

1410-607: 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. 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

1504-454: 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. 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

1598-454: 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. 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

1692-463: A patent for the design of a cloverleaf interchange on May   24, 1915, 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

1786-597: A removed left entrance from Broadway. The ramp from US 6 east to Westminster Street was also closed around this time, leaving its ramp to Broadway. The other part of the Connector opened in 1988, connecting the Huntington Expressway and Olneyville Bypass to Interstate 95 in downtown Providence. US 6 was rerouted along the Connector and I-95 to reach Interstate 195 . The ramps to downtown, connecting to Memorial Boulevard, did not open until 1993, as part of

1880-439: 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. Parclo configurations are given names based on the location of and number of quadrants with ramps. The letter A denotes that, for traffic on

1974-439: 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. Parclo configurations are given names based on the location of and number of quadrants with ramps. The letter A denotes that, for traffic on

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2068-543: 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. A double roundabout diamond interchange, also known as

2162-543: 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. A double roundabout diamond interchange, also known as

2256-401: A three-level semi-directional T at Highway 407 and a two-level semi-directional T at Highway 401 . 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. A diamond interchange is an interchange involving four ramps where they enter and leave the freeway at

2350-401: A three-level semi-directional T at Highway 407 and a two-level semi-directional T at Highway 401 . 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. A diamond interchange is an interchange involving four ramps where they enter and leave the freeway at

2444-509: 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 interchanges are built as two- or three-level junctions, with three-level interchanges typically used in urban or suburban areas where land

2538-509: 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 interchanges are built as two- or three-level junctions, with three-level interchanges typically used in urban or suburban areas where land

2632-442: 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. 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. A full Y-interchange (also known as

2726-442: 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. 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. A full Y-interchange (also known as

2820-422: A traditional stack interchange. A three-level roundabout interchange features a grade-separated roundabout which handles traffic exchanging between highways. 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. These interchanges can also be used to make a "linking road" to the destination for a service interchange, or

2914-422: A traditional stack interchange. A three-level roundabout interchange features a grade-separated roundabout which handles traffic exchanging between highways. 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. These interchanges can also be used to make a "linking road" to the destination for a service interchange, or

Rhode Island Route 10 - Misplaced Pages Continue

3008-415: Is a controlled-access highway (freeway) or a limited-access highway (expressway), though they are sometimes used at junctions between surface streets. 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. The concept of

3102-435: 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

3196-446: Is a 3-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 4-level stack. Stacks are significantly more expensive than other four-way interchanges are 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

3290-446: Is a 3-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 4-level stack. Stacks are significantly more expensive than other four-way interchanges are 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

3384-428: 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 requires more land to construct than a four-level stack interchange; however,

3478-428: 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 requires more land to construct than a four-level stack interchange; however,

3572-477: Is braided when at least one of the roadways reverses sides. It seeks to make left and right turns equally easy. 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 ; however, the interchange was reconfigured in 2008 to

3666-421: Is braided when at least one of the roadways reverses sides. It seeks to make left and right turns equally easy. 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 ; however, the interchange was reconfigured in 2008 to

3760-483: Is in Providence County . Interchange (road) 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

3854-601: Is just after the Cranston Street interchange, where Niantic Avenue ends. Upon crossing into Providence Route 10 passes over and parallels the Northeast Corridor as well as interchanging with Huntington Avenue. From this interchange north to Olneyville , Huntington Avenue was upgraded to become the Huntington Expressway. Within this stretch of expressway, there is only one interchange (Union Avenue). The junction and merge with U.S. Route 6 at Olneyville

Rhode Island Route 10 - Misplaced Pages Continue

3948-470: 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

4042-470: 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

4136-575: Is now made with a left turn onto Route 12. There were once plans to extend Route 10 south, in conjunction with an eastern extension of the Route 37 freeway. Route 10 heads north through Providence, turning west before crossing U.S. Route 1 (Elmwood Avenue) at a partial interchange. There is no ramp to Route 10 south, and traffic exiting from Route 10 north must turn north on US 1. After crossing US 1, Route 10 crosses over Amtrak 's Northeast Corridor and enters Cranston. Route 10 crosses Interstate 95 at

4230-416: Is now one-way “eastbound,” or what would have been northbound RI 10), Veazie Street, and Branch Avenue to end at Route 146 . The Route 12 interchange was not the planned end of the freeway; it was to continue roughly parallel to Route 117 and Route 117A , meeting Route 37 and ending near the south end of Route 117A. For a time, Interstate 84 was planned to enter Providence via Olneyville. One plan by

4324-614: Is part of the Olneyville Bypass , the first freeway in Rhode Island. In the early 2020s, this current interchange was upgraded to conform to modern highway standards, most notably providing direct access from Route 10 North to US 6 West via a flyover ramp (Exit 3B). The flyover ramp officially opened on November 19, 2021. Exit 3B is a left-lane exit to US 6, while mainline traffic remains on the right heading into Downtown Providence. The combined Route 10 and US 6 - known as

4418-486: Is provided by ramps to the west end of Memorial Boulevard at Francis Street ( U.S. Route 1 ). Despite the first section opening in 1953, the Route 10 designation was not used until 1966, when the freeway south of Route 2 (Reservoir Avenue) opened. The 1953 section was the Olneyville Bypass (also known as the Dennis J. Roberts Expressway , now also applied to U.S. Route 6 west of the bypass). Construction began in 1950 on

4512-405: The Route 6-10 Connector - is the newest part of the Huntington Expressway. It heads northeast and east from Olneyville, interchanging with Dean Street (which provides access to Providence Place Mall ). East of Dean Street, the freeway ends at a complicated interchange with Interstate 95 . Route 10 ends there, while US 6 turns south with I-95 to reach Interstate 195 . Access to downtown Providence

4606-400: 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

4700-400: 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

4794-537: The left side of the bridge, contrary to most of the United States. The rebuild is expected to be completed in 2023. Exits were previously unnumbered, but RIDOT numbered exits between the southern terminus and the U.S. Route 6 concurrency in late 2010 to conform with federal highway standards. "Old" (2010-2020) exit numbers courtesy of RIDOT. In 2020, RIDOT renumbered the exits as part of a statewide project to convert to mileage based numbering. The entire route

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4888-403: 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

4982-403: 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

5076-485: The United States opened on July   7, 2009, in Springfield, Missouri , at the junction of Interstate 44 and Missouri Route 13 . 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

5170-426: The United States opened on July   7, 2009, in Springfield, Missouri , at the junction of Interstate 44 and Missouri Route 13 . 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

5264-401: The bridges are generally short in length. Coupled with reduced maintenance costs, a turbine interchange is a less costly alternative to a stack. 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

5358-401: The bridges are generally short in length. Coupled with reduced maintenance costs, a turbine interchange is a less costly alternative to a stack. 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

5452-429: The bypass of the congested Olneyville neighborhood, which the east–west US 6 and Route 14 passed through (on Westminster Street, Hartford Avenue and Plainfield Street). The bypass ran from Hartford Avenue west of Olneyville around the south and east sides of Olneyville, junctioning with Plainfield Street, Huntington Avenue, Westminster Street and Broadway, and ending at Harris Avenue northeast of Olneyville. Once

5546-469: The bypass opened in 1953, it carried US 6. Eastbound US 6 exited at Westminster Street to follow its old alignment towards downtown, but westbound US 6 was completely rerouted between downtown and Olneyville, following Kinsley Avenue, Eagle Street and Harris Avenue to reach the Olneyville Bypass. The next section, from Olneyville south to Reservoir Avenue in Cranston , was built partially along

5640-507: 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. Since single-point urban interchanges can exist in rural areas, such as the interchange of U.S. Route 23 with M-59 in Michigan ;

5734-452: 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. Since single-point urban interchanges can exist in rural areas, such as the interchange of U.S. Route 23 with M-59 in Michigan ;

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5828-501: 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 and Long Island Motor Parkway were the first roads to feature grade-separations. Maryland engineer Arthur Hale filed

5922-537: The creation of a new basic road as a service 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 . 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

6016-537: The creation of a new basic road as a service 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 . 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

6110-448: The diverging windmill, increases capacity by altering the direction of traffic flow of the interchanging highways, making the connecting ramps much more direct. 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. A braided or diverging interchange is a two-level, four-way interchange. An interchange

6204-448: The diverging windmill, increases capacity by altering the direction of traffic flow of the interchanging highways, making the connecting ramps much more direct. 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. A braided or diverging interchange is a two-level, four-way interchange. An interchange

6298-427: The early Huntington Expressway, from Route 2 southeast across Interstate 95 and US 1 to Route 12 , was completed in 1966. It was then that the Route 10 designation was applied, and Route 2 was moved back to its present alignment. However, Route 10 did not end at Olneyville - it continued to the end of the bypass at Harris Avenue, and then took Harris Avenue, Eagle Street, Valley Street, River Avenue, Oneil Street (which

6392-544: The existing Huntington Avenue, and opened in 1960. It ended at a temporary trumpet interchange with Reservoir Avenue, which at the time carried both Route 2 and Route 3 . (Route 3 has since been truncated to its intersection with Route 2 in West Warwick .) Route 2 was rerouted onto the new Huntington Expressway to end at US 6 at Olneyville, while Route 3 continued to run to U.S. Route 1 in Providence. The rest of

6486-415: The first roads to feature grade-separations. Maryland engineer Arthur Hale filed a patent for the design of a cloverleaf interchange on May   24, 1915, 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

6580-439: 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 a limited-access highway (expressway), though they are sometimes used at junctions between surface streets. Note: The descriptions of interchanges apply to countries where vehicles drive on

6674-594: The opposite direction of travel and saves one signal phase of traffic lights each. 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. 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 . The first DDI in

6768-493: The opposite direction of travel and saves one signal phase of traffic lights each. 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. 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 . The first DDI in

6862-513: 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

6956-458: 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

7050-543: The portmanteau, cloverstack ) 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. 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. Some turbine-stack hybrids: The turbine interchange

7144-543: The portmanteau, cloverstack ) 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. 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. Some turbine-stack hybrids: The turbine interchange

7238-467: 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 4-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

7332-467: 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 4-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

7426-452: The redevelopment of downtown. In November 2021, as an early stage of reconstructing the Route 10/US 6 interchange, a new ramp was opened, allowing direct movements from northbound Route 10 to westbound US 6 for the first time. The following year, the ramp in the opposite direction (US 6 eastbound to RI 10 southbound) was temporarily removed, so for over 12 months, traffic was required to use a temporary ramp to Westminster Street and drive along

7520-535: 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. 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 and Long Island Motor Parkway were

7614-455: 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 on-ramp merges both streams of incoming traffic into the left-bound highway. As there is only one off-ramp and one on-ramp (in that respective order), stacks do not suffer from

7708-455: 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 on-ramp merges both streams of incoming traffic into the left-bound highway. As there is only one off-ramp and one on-ramp (in that respective order), stacks do not suffer from

7802-421: The road is extended. US 70 and US 17 west of New Bern, North Carolina is an example. 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 off-ramp. Assuming right-handed driving, to cross over incoming traffic and go left, vehicles first exit onto an off-ramp from

7896-421: The road is extended. US 70 and US 17 west of New Bern, North Carolina is an example. 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 off-ramp. Assuming right-handed driving, to cross over incoming traffic and go left, vehicles first exit onto an off-ramp from

7990-526: The state designated the Huntington Expressway south of Olneyville as Interstate 184 ( I-184 ) , but this was rejected by the Federal Highway Administration . The first section of the Route 6-10 Connector , from the east end of the Olneyville Bypass to Dean Street, opened in 1972. At that time, Route 10 was removed from its former surface alignment to a temporary end at Dean Street. The ramp it had taken northbound to Harris Avenue

8084-648: The term single-point diamond interchange is considered the correct phrasing. 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 . Trumpet interchange In the field of road transport , an interchange (American English) or a grade-separated junction (British English)

8178-502: 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 5-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

8272-443: 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 5-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

8366-540: Was considered a revolutionary design at the time of its construction. 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 . Some may be half cloverleaf containing ghost ramps which can be upgraded to full cloverleafs if

8460-540: Was considered a revolutionary design at the time of its construction. 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 . Some may be half cloverleaf containing ghost ramps which can be upgraded to full cloverleafs if

8554-400: Was cut by the new construction, but the abutments for the bridge over the Northeast Corridor and northbound Harris Avenue remained until the early 2020s, when the Route 10/US 6 interchange was rebuilt. US 6 westbound was not moved in 1972, but left to continue to enter the Olneyville Bypass from Harris Avenue at that time. A new ramp from Tobey Street to the bypass was added, however, replacing

8648-436: Was designed by Philadelphia engineering firm Rudolph and Delano, based on a design seen in an Argentinian magazine. A system interchange connects multiple controlled-access highways, involving no at-grade signalised intersections. A cloverleaf interchange is a four-legged junction where left turns across opposing traffic are handled by non-directional loop ramps. It is named for its appearance from above, which resembles

8742-596: Was designed by Philadelphia engineering firm Rudolph and Delano based on a design seen in an Argentinian magazine. The first cloverleaf in Canada opened in 1938 at the junction of Highway 10 and what would become the Queen Elizabeth Way . 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

8836-417: Was designed by Philadelphia engineering firm Rudolph and Delano based on a design seen in an Argentinian magazine. The first cloverleaf in Canada opened in 1938 at the junction of Highway 10 and what would become the Queen Elizabeth Way . 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

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