Category:234 Interchanges - Revision history

Smithk: Updated website link for increased security

2021-10-25T17:53:31Z

Updated website link for increased security

← Older revision		Revision as of 12:53, 25 October 2021
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	Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.		Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.

	[[Image:234.2 DDI.jpg\|thumb\|left\|<center>[~~http~~://epg.modot.~~mo.gov~~/documents/234.2_DDI_Animation.mpg '''Diverging Diamond Interchange Animation''']'''</center>]]		[[Image:234.2 DDI.jpg\|thumb\|left\|<center>[https://epg.modot.org/documents/234.2_DDI_Animation.mpg '''Diverging Diamond Interchange Animation''']'''</center>]]
	In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.		In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.

	The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.		The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.

Smithk at 19:24, 27 November 2012

2012-11-27T19:24:23Z

← Older revision		Revision as of 14:24, 27 November 2012
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	Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.		Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.
	{\|style="padding: 0.3em; margin-~~right~~:~~5px~~; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="160px" align="right"		{\|style="padding: 0.3em; margin-left:9px; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="160px" align="right"
	\|-		\|-
	\|'''Additional Information'''		\|'''Additional Information'''
	\|-		\|-
	\|[http://www.fhwa.dot.gov/publications/research/safety/09060/ FHWA's Alternative Intersections/Interchanges~~: Informational~~ Report]		\|[http://www.fhwa.dot.gov/publications/research/safety/09060/ FHWA's Alternative Intersections/Interchanges Report]
	\|}		\|}
	Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.		Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.

Smithk: Per Traffic, added FHWA report link

2012-11-27T18:07:15Z

Per Traffic, added FHWA report link

← Older revision		Revision as of 13:07, 27 November 2012
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	Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.		Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.
			{\|style="padding: 0.3em; margin-right:5px; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="160px" align="right"
			\|-
			\|'''Additional Information'''
			\|-
			\|[http://www.fhwa.dot.gov/publications/research/safety/09060/ FHWA's Alternative Intersections/Interchanges: Informational Report]
			\|}
	Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.		Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.

Smithk at 13:28, 22 April 2011

2011-04-22T13:28:44Z

← Older revision		Revision as of 08:28, 22 April 2011
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	The selection of an appropriate interchange is influenced by such factors as highway classification, composition of traffic, anticipated operating speed, economics, terrain, available right of way and the degree of access control. An interchange is to be considered when warranted by the 20-year design traffic projection or safety concerns. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.		The selection of an appropriate interchange is influenced by such factors as highway classification, composition of traffic, anticipated operating speed, economics, terrain, available right of way and the degree of access control. An interchange is to be considered when warranted by the 20-year design traffic projection or safety concerns. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.

	At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 Access to Interstate Highways		At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 Access to Interstate Highways\|access approval]] for new or revised access must be provided to FHWA for approval during the project development process and prior to making any changes to the interstate access.
	\|access approval]] for new or revised access must be provided to FHWA for approval during the project development process and prior to making any changes to the interstate access.

	Basic types of interchanges are:		Basic types of interchanges are:

Smithk: upated link

2011-04-22T13:28:20Z

upated link

← Older revision		Revision as of 08:28, 22 April 2011
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	The selection of an appropriate interchange is influenced by such factors as highway classification, composition of traffic, anticipated operating speed, economics, terrain, available right of way and the degree of access control. An interchange is to be considered when warranted by the 20-year design traffic projection or safety concerns. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.		The selection of an appropriate interchange is influenced by such factors as highway classification, composition of traffic, anticipated operating speed, economics, terrain, available right of way and the degree of access control. An interchange is to be considered when warranted by the 20-year design traffic projection or safety concerns. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.

	At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 ~~Interchange Justification for~~ Interstate Highways\|~~justification~~]] for new or revised access must be provided to FHWA for approval during the project development process and prior to making any changes to the interstate access.		At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 Access to Interstate Highways
			\|access approval]] for new or revised access must be provided to FHWA for approval during the project development process and prior to making any changes to the interstate access.

	Basic types of interchanges are:		Basic types of interchanges are:

Smithk: Access Justification Report (AJR) info updated to comply with current FHWA practice, per Design

2011-04-22T12:54:45Z

Access Justification Report (AJR) info updated to comply with current FHWA practice, per Design

← Older revision		Revision as of 07:54, 22 April 2011
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	\|[[Image:234 Photo5 DDI.jpg\|thumb\|<center>'''Diverging Diamond Interchange'''</center>]]		\|[[Image:234 Photo5 DDI.jpg\|thumb\|<center>'''Diverging Diamond Interchange'''</center>]]
	\|}		\|}
			Interchanges are considered where conflicting high traffic volumes exceed those that can be handled efficiently and safely with at-grade intersections. They are also used to control access to the main highway. The location study for a proposed improvement recommends the type and location of a proposed interchange necessary to address these concerns. A precise analysis of traffic movement that justifies the necessity for an interchange is required. Depending on the complexity, appropriate modeling can include microsimulation or analysis using the ''Highway Capacity Manual''. Access management guidelines are considered in analysis of operational and safety concerns.

	~~The selection of~~ an ~~appropriate~~ interchange ~~is influenced by such factors as~~ highway ~~classification~~, ~~composition~~ of ~~traffic~~, ~~anticipated operating speed, economics, terrain, available~~ right of way ~~and~~ the ~~degree~~ of ~~access control. An interchange is to be considered when warranted by~~ the ~~20-year design traffic projection or safety concerns. An~~ interchange will ~~provide access~~ for ~~all~~ traffic movements. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.		MoDOT intends to provide access for all traffic movements at an interchange on the state highway system. In some cases, traffic volumes may not warrant the provision of ramps at the time of initial construction. However, right of way should be purchased to provide for the future ramps. The plans for initial construction of the interchange will show the location of future ramps for these traffic movements.

	At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 Interchange Justification for Interstate Highways\|justification]] must be provided to FHWA for approval ~~before~~ the ~~work can begin~~.		The selection of an appropriate interchange is influenced by such factors as highway classification, composition of traffic, anticipated operating speed, economics, terrain, available right of way and the degree of access control. An interchange is to be considered when warranted by the 20-year design traffic projection or safety concerns. The desired spacing between interchanges is two miles in current and projected urban areas and five miles in rural areas. [[:category:940 Access Management\|Access Management Guidelines]] are also considered to determine the spacing of interchanges.

			At times it may be necessary to construct a new interchange or revise an existing interchange on an interstate highway. When this occurs, [[234.1 Interchange Justification for Interstate Highways\|justification]] for new or revised access must be provided to FHWA for approval during the project development process and prior to making any changes to the interstate access.

	Basic types of interchanges are:		Basic types of interchanges are:

Smithk: Updated to accommodate new EPG 234.6 DDI

2010-07-09T15:31:28Z

Updated to accommodate new EPG 234.6 DDI

← Older revision		Revision as of 10:31, 9 July 2010
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	{\|align="right"		{\|align="right"
	\|-		\|-
	\|[[Image:234 Photo 1 Diamond Interchange.jpg\|thumb\|<center>Diamond Interchange</center>]]		\|[[Image:234 Photo 1 Diamond Interchange.jpg\|thumb\|<center>'''Diamond Interchange'''</center>]]
	\|-		\|-
	\|[[Image:234 Photo2 Directional Interchange.jpg\|thumb\|<center>Directional Interchange</center>]]		\|[[Image:234 Photo2 Directional Interchange.jpg\|thumb\|<center>'''Directional Interchange'''</center>]]
	\|-		\|-
	\|[[Image:234 Photo3 Single Point Interchange.jpg\|thumb\|<center>Single Point Interchange</center>]]		\|[[Image:234 Photo3 Single Point Interchange.jpg\|thumb\|<center>'''Single Point Interchange'''</center>]]
	\|-		\|-
	\|[[Image:234 Photo4 Cloverleaf Interchange.jpg\|thumb\|<center>Cloverleaf Interchange</center>]]		\|[[Image:234 Photo4 Cloverleaf Interchange.jpg\|thumb\|<center>'''Cloverleaf Interchange'''</center>]]
			\|-
			\|[[Image:234 Photo5 DDI.jpg\|thumb\|<center>'''Diverging Diamond Interchange'''</center>]]
	\|}		\|}

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	* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single Point]]		* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single Point]]
	* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]		* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]
			* [[234.6 Diverging Diamond Interchanges\|Diverging Diamond]]

	Chapter 10 of the AASHTO Green Book provides examples of these interchange types. Controlling factors in the selection of an interchange type are: right of way requirements, vehicle speed, traffic volume, terrain, access control and cost. Interchanges are designed to fit specific local conditions and meet driver expectations.		Chapter 10 of the AASHTO Green Book provides examples of these interchange types. Controlling factors in the selection of an interchange type are: right of way requirements, vehicle speed, traffic volume, terrain, access control and cost. Interchanges are designed to fit specific local conditions and meet driver expectations.
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	Directional interchanges accommodate high volume turning movements where two freeways intersect. Direct ramp movements reduce travel distance, increase speed and capacity, eliminate weaving and avoid the need for “out-of-direction” travel on a loop. These interchanges are costly to construct due to the increased number and length of ramps and the number of bridge crossings.		Directional interchanges accommodate high volume turning movements where two freeways intersect. Direct ramp movements reduce travel distance, increase speed and capacity, eliminate weaving and avoid the need for “out-of-direction” travel on a loop. These interchanges are costly to construct due to the increased number and length of ramps and the number of bridge crossings.

	Single-point urban interchanges (SPUI) were first constructed in the early ~~1970’s~~. Their primary feature is all four turning movements intersect at a common point. Therefore, the number of signals needed to control traffic is reduced. Furthermore, opposing left turn movements pass to the left of each other		Single-point urban interchanges (SPUI) were first constructed in the early 1970s. Their primary feature is all four turning movements intersect at a common point. Therefore, the number of signals needed to control traffic is reduced. Furthermore, opposing left turn movements pass to the left of each other

	Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.		Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.

	[[Image:234.2 DDI.jpg\|thumb\|left\|<center>Diverging Diamond Interchange ~~(DDI)~~</center>]]		Diverging diamond interchanges (DDI) are diamond interchanges that more efficiently facilitates heavy left-turn movements. While the ramp configuration is similar to a traditional diamond interchange, traffic on the crossroad moves to the left side of the roadway for the segment between signalized ramp intersections.

			[[Image:234.2 DDI.jpg\|thumb\|left\|<center>[http://epg.modot.mo.gov/documents/234.2_DDI_Animation.mpg '''Diverging Diamond Interchange Animation''']'''</center>]]
	In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.		In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.
	~~{\|style="padding: 0.3em; margin-left:10px; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="200px" align="right"~~
	\|-		The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.
	~~\|'''Video'''~~
	\|-
	~~\|[http://www.youtube.com/v/B5JtZMPTNAY&hl=en&fs=1&rel=0 '''What Does a DDI Look Like?''']~~
	\|}
	The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.

Smithk: article construction

2009-08-06T15:52:09Z

article construction

← Older revision		Revision as of 10:52, 6 August 2009
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	[[Image:234.2 DDI.jpg\|thumb\|left\|<center>Diverging Diamond Interchange (DDI)</center>]]		[[Image:234.2 DDI.jpg\|thumb\|left\|<center>Diverging Diamond Interchange (DDI)</center>]]
	In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.		In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.
			{\|style="padding: 0.3em; margin-left:10px; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="200px" align="right"
			\|-
			\|'''Video'''
			\|-
			\|[http://www.youtube.com/v/B5JtZMPTNAY&hl=en&fs=1&rel=0 '''What Does a DDI Look Like?''']
			\|}
	The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.		The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.

EPG-Admin at 20:50, 19 December 2006

2006-12-19T20:50:52Z

← Older revision		Revision as of 15:50, 19 December 2006
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	Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.		Cloverleaf interchanges can be used where two high volume freeways intersect. Loop-ramps are used to accommodate left-turning movements. However, this configuration provides short weaving areas for traffic entering or leaving the interchange. A cloverleaf interchange occupies a relatively large area of right of way.

			[[Image:234.2 DDI.jpg\|thumb\|left\|<center>Diverging Diamond Interchange (DDI)</center>]]
	In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.		In some circumstances, a “basic” interchange may not be the appropriate choice to satisfy the needs of the traveling public. The interchange that is designed may be a combination of the basic types or incorporate [[Media:234.2 Creative Diamnond Interchange Arrangements.pdf\|creative modifications]]. A Diverging Diamond Interchange (DDI) is one example.

	The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.		The high cost of construction restricts the use of an interchange to those situations where the expenditure is justified. An interchange “warrants” construction based on consideration of the roadway’s design designation, traffic volume and safety of operation.

EPG-Admin at 13:12, 14 December 2006

2006-12-14T13:12:32Z

← Older revision		Revision as of 08:12, 14 December 2006
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	* [[234.2 Diamond Interchanges\|Diamond]]		* [[234.2 Diamond Interchanges\|Diamond]]
	* [[234.3 Directional Interchanges\|Directional]]		* [[234.3 Directional Interchanges\|Directional]]
	* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single]]		* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single Point]]
	* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]		* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]

← Older revision		Revision as of 08:12, 14 December 2006
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	* [[234.2 Diamond Interchanges\|Diamond]]		* [[234.2 Diamond Interchanges\|Diamond]]
	* [[234.3 Directional Interchanges\|Directional]]		* [[234.3 Directional Interchanges\|Directional]]
	* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single]]		* [[234.4 Single Point Urban Interchanges (SPUIs)\|Single Point]]
	* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]		* [[234.5 Cloverleaf Interchanges\|Cloverleaf]]