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Free-flow Interchange
A free-flow interchange is an interchange in which all roads are grade-separated, and where movement from one road to another does not require the driver to stop for traffic (for example, the interchange may not include traffic lights or unsignalized at-grade intersections). Free-flow interchanges are less likely to induce traffic congestion than non-free-flow, but are typically more expensive both in money and in land. Some free-flow interchanges bring additional problems such as weaving or passing lane/fast lane exits (i.e. left exits in areas with right-hand traffic, and vice versa) that may be necessary to avoid additional costs, but lead to congestion and accidents and ultimately to an upgrade to another type of interchange. A free flow interchange design, called double crossover merging interchange (DCMI), has received a patent."United States Patent 8,950,970: Double Crossover Merging Interchange". United States Patent and Trademark Office. February 10, 2015. Retrieved A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 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. Terminology ''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 juncti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trumpet Interchange
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. Terminology ''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, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Road Interchanges
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of roads, including parkways, avenues, controlled-access highways (freeways, motorways, and expressways), tollways, interstates, highways, thoroughfares, and local roads. The primary features of roads include lanes, sidewalks (pavement), roadways (carriageways), medians, shoulders, verges, bike paths (cycle paths), and shared-use paths. Definitions Historically many roads were simply recognizable routes without any formal construction or some maintenance. The Organization for Economic Co-operation and Development (OECD) defines a road as "a line of communication (travelled way) using a stabilized base other than rails or air strips open to public traffic, primarily for the use of road motor vehicles running on their own wheels", which i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diverging Diamond Interchange
A diverging diamond interchange (DDI), also called a double crossover diamond interchange (DCD), is a subset of diamond interchange in which the opposing directions of travel on the non-freeway road cross each other on either side of the interchange so that traffic crossing the freeway on the overpass or underpass is operating on the opposite driving side from that which is customary for the jurisdiction. The crossovers may employ one-side overpasses or be at-grade and controlled by traffic light. The diverging diamond interchange has advantages in both efficiency and safety, and—despite having been in use in France since the 1970s—was cited by ''Popular Science'' as one of the best engineering innovations of 2009 and in the U.S. has been promoted as part of the Federal Highway Administration's Every Day Counts initiative. The flow through a diverging diamond interchange using overpasses at the crossovers is limited only by weaving, and the flow through an implementation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-level Diamond Interchange
A three-level diamond interchange is a type of highway interchange where through traffic on both main roads is grade-separated from intersections which handle transferring traffic. It is similar in design to a three-level stacked roundabout except for its use of (usually signalled) conventional intersections, and can be thought of as two diamond interchanges fused together. Road enthusiasts sometimes use the terms volleyball interchange or split-level diamond interchange to refer to these interchanges. Description In a three-level diamond interchange, the two main roads are on separate levels, and on a third level, usually in the middle, there is a square of one-way roads. The square circulates clockwise where traffic drives on the left, or anticlockwise where it drives on the right. At each corner of the square is the terminal of an exit ramp from one main road and an entrance ramp to the other main road. Traffic transferring from one road to the other to make an overall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Partial Cloverleaf Interchange
A partial cloverleaf interchange or parclo is a modification of a cloverleaf interchange. The design has been well received, and has since become one of the most popular freeway-to-arterial interchange designs in North America. It has also been used occasionally in some European countries, such as Germany, Hungary, Italy, the Netherlands, and the United Kingdom. Comparison with other interchanges *A diamond interchange has four ramps. *A cloverleaf interchange has eight ramps, as does a stack interchange. They are fully grade separated, unlike a parclo, and have traffic flow without stops on all ramps and throughways. *A parclo generally has either four or six ramps but less commonly has five ramps. Naming In Ontario, the specific variation is identified by a letter/number suffix after the name. Ontario's naming conventions are used in this article. The letter ''A'' designates that two ramps meet the freeway ''ahead'' of the arterial road, while ''B'' designates that two ram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Interchange
A diamond interchange is a common type of road junction, used where a controlled-access highway crosses a minor road. Design The freeway itself is grade-separated from the minor road, one crossing the other over a bridge. Approaching the interchange from either direction, an off-ramp diverges only slightly from the freeway and runs directly across the minor road, becoming an on-ramp that returns to the freeway in similar fashion. The two places where the ramps meet the road are treated as conventional intersections. In the United States, where this form of interchange is very common, particularly in rural areas, traffic on the off-ramp typically faces a stop sign at the minor road, while traffic turning onto the freeway is unrestricted. The diamond interchange uses less space than most types of freeway interchange, and avoids the interweaving traffic flows that occur in interchanges such as the cloverleaf. Thus, diamond interchanges are most effective in areas where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloverleaf Interchange
A cloverleaf interchange is a two-level interchange in which all turns are handled by slip roads. To go left (in right-hand traffic; reverse directions in left-driving regions), vehicles first continue as one road passes over or under the other, then exit right onto a one-way three-fourths loop ramp (270°) and merge onto the intersecting road. The objective of a cloverleaf is to allow two highways to cross without the need for any traffic to be stopped by traffic lights. The limiting factor in the capacity of a cloverleaf interchange is traffic weaving. Overview Cloverleaf interchanges, viewed from overhead or on maps, resemble the leaves of a four-leaf clover or less often a 3-leaf clover. In the United States, cloverleaf interchanges existed long before the Interstate system. They were originally created for busier interchanges that the original diamond interchange system could not handle. Their chief advantage was that they were free-flowing and did not require t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grade Separation
In civil engineering (more specifically highway engineering), grade separation is a method of aligning a junction of two or more surface transport axes at different heights (grades) so that they will not disrupt the traffic flow on other transit routes when they cross each other. The composition of such transport axes does not have to be uniform; it can consist of a mixture of roads, footpaths, railways, canals, or airport runways. Bridges (or overpasses, also called flyovers), tunnels (or underpasses), or a combination of both can be built at a junction to achieve the needed grade separation. In North America, a grade-separated junction may be referred to as a ''grade separation'' or as an '' interchange'' – in contrast with an '' intersection'', ''at-grade'', a ''diamond crossing'' or a ''level crossing'', which are not grade-separated. Effects Advantages Roads with grade separation generally allow traffic to move freely, with fewer interruptions, and at higher overall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stack Interchange
A directional interchange, colloquially known as a stack interchange, is a type of grade-separated junction between two controlled-access highways that allows for free-flowing movement to and from all directions of traffic. These interchanges eliminate the problems of weaving, have the highest vehicle capacity, and vehicles travel shorter distances when compared to different types of interchanges. The first directional interchange built in the world was the Four Level Interchange which opened to Los Angeles traffic in 1949. Definition A directional interchange is a grade separated junction between two roads where all turns that require crossing over or under the opposite road's lanes of travel in order to complete the turn utilize ramps that make a direct or semi-direct connection. The difference between direct and semi-direct connections is how much the motorist deviates from the intended direction of travel while on the ramp; direct ramps are shorter and can handle higher t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamond Interchange
A diamond interchange is a common type of road junction, used where a controlled-access highway crosses a minor road. Design The freeway itself is grade-separated from the minor road, one crossing the other over a bridge. Approaching the interchange from either direction, an off-ramp diverges only slightly from the freeway and runs directly across the minor road, becoming an on-ramp that returns to the freeway in similar fashion. The two places where the ramps meet the road are treated as conventional intersections. In the United States, where this form of interchange is very common, particularly in rural areas, traffic on the off-ramp typically faces a stop sign at the minor road, while traffic turning onto the freeway is unrestricted. The diamond interchange uses less space than most types of freeway interchange, and avoids the interweaving traffic flows that occur in interchanges such as the cloverleaf. Thus, diamond interchanges are most effective in areas where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
