Diamond interchange
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▪ Most common interchange configuration; therefore, it meets driver expectation. ▪ Well suited for both rural and urban use. ▪ Adaptable in major-minor road crossings where grade crossings on the minor roadway can be handled with minimal interference to traffic approaching the intersection from any direction. ▪ Lower cost than other interchange configurations. ▪ Requires less right of way than Design of diamond inter change 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 traffic is light and a more expensive interchange type is not needed. But where traffic volumes are higher, the two intersections within the interchange often feature additional traffic control measures such as traffic lights and extra lanes dedicated to turning traffic. A diamond interchange is a common type of road junction, used where a freeway crosses a minor road. Visual showing how diamond interchanges are used, with an expressway running across and a local road running in the center. Left image is for left-side traffic (UK), right image is for right-side traffic (U.S.). Large arrows show where turns are made; smaller arrows show traffic flow. 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. Introduction Types Other Dumbbell Disadvantages Where HOV lanes are present for carpooling, the ramps of a diamond interchange may be folded to the inside lanes instead of the outside. In urban areas this saves some space as well as requiring only one intersection instead of the two one- way intersections, which in rural or suburban areas can be turned into a single-point urban interchange. This in turn reduces waiting time for motorists at traffic lights on the smaller road, which may be a large local thoroughfare with heavy traffic. The ramp intersections may also be configured as a pair of roundabouts to create a type of diamond interchange often called a dumbbell interchange Advantages Dog Bone A variation of the dumbbell interchange, often called a dog bone interchange (due to its aerial resemblance to a real or toy dog bone), and sometimes also called a double roundabout interchange. Tight Diamond A tight diamond interchange (TDI), also known as a compressed diamond interchange or a tight urban diamond interchange (TUDI), is sometimes used in areas where there is insufficient right-of-way for a standard diamond interchange. Single-point Urban A Single-point urban interchange (SPUI) is built with a large over- or clear underpass providing space for a single traffic signal controlled intersection with the ramps and the cross street. Diverging Diamond In a Diverging diamond interchange (DDI) or (DCD), on the bridge the roadways of the cross street are being exchanged like left-hand traffic to save the third traffic signal phase. Three-level Diamond In a Three-level diamond interchange, the cross street is built in a third level with free flowing traffic as a second arterial road. The intersection is split up into four intersections, handling just two conflicting directions each. ▪ Possible wrong-way entry on the ramps from the crossroad must be addressed. ▪ The greatest impediment to smooth operation is the left-turning traffic at the crossroad intersections. ▪ Level of service decreases as the volume of traffic on the crossroad becomes heavy. Turja Deb Mitun ID:1301060028 Presented By:
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Transcript of Diamond interchange
▪ Most common interchange configuration; therefore, it meets driver expectation.
▪ Well suited for both rural and urban use.
▪ Adaptable in major-minor road crossings where grade crossings on the minor roadway can be handled with minimal interference to traffic approaching the intersection from any direction.
▪ Lower cost than other interchange configurations.
▪ Requires less right of way than other types of interchanges.
Design of diamond inter change
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 traffic is light and a more expensive interchange type is not needed. But where traffic volumes are higher, the two intersections within the interchange often feature additional traffic control measures such as traffic lights and extra lanes dedicated to turning traffic.
A diamond interchange is a common type of road junction, used where a freeway crosses a minor road.
Visual showing how diamond interchanges are used, with an expressway running across and a local road running in the center. Left image is for left-side traffic (UK), right image is for right-side traffic (U.S.). Large arrows show where turns are made; smaller arrows show traffic flow.
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.
Introduction Types Other
Dumbbell
Disadvantages
Where HOV lanes are present for carpooling, the ramps of a diamond interchange may be folded to the inside lanes instead of the outside. In urban areas this saves some space as well as requiring only one intersection instead of the two one-way intersections, which in rural or suburban areas can be turned into a single-point urban interchange. This in turn reduces waiting time for motorists at traffic lights on the smaller road, which may be a large local thoroughfare with heavy traffic.
The ramp intersections may also be configured as a pair of roundabouts to create a type of diamond interchange often called a dumbbell interchange
Advantages
Dog Bone
A variation of the dumbbell interchange, often called a dog bone interchange (due to its aerial resemblance to a real or toy dog bone), and sometimes also called a double roundabout interchange.
Tight DiamondA tight diamond interchange (TDI), also known as a compressed diamond interchange or a tight urban diamond interchange (TUDI), is sometimes used in areas where there is insufficient right-of-way for a standard diamond interchange.
Single-point Urban
A Single-point urban interchange (SPUI) is built with a large over- or clear underpass providing space for a single traffic signal controlled intersection with the ramps and the cross street.
Diverging Diamond
In a Diverging diamond interchange (DDI) or (DCD), on the bridge the roadways of the cross street are being exchanged like left-hand traffic to save the third traffic signal phase.
Three-level DiamondIn a Three-level diamond interchange, the cross street is built in a third level with free flowing traffic as a second arterial road. The intersection is split up into four intersections, handling just two conflicting directions each.
▪ Possible wrong-way entry on the ramps from the crossroad must be addressed.▪ The greatest impediment to smooth operation is the left-turning traffic at the crossroad intersections.▪ Level of service decreases as the volume of traffic on the crossroad becomes heavy.
Turja Deb Mitun ID:1301060028
Presented By:
