234.6 Diverging Diamond Interchanges - Revision history

Hoskir: /* 234.6.1 Introduction */ fixed link to Lessons, 2010

2024-09-19T18:09:08Z

234.6.1 Introduction: fixed link to Lessons, 2010

← Older revision		Revision as of 13:09, 19 September 2024
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	\|'''Diverging Diamond Interchange'''		\|'''Diverging Diamond Interchange'''
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	\|[https://~~spexternal~~.~~modot~~.~~mo.gov~~/~~sites~~/cm/~~CORDT~~/~~or10021_ReportNoApp.pdf~~ Lessons, 2010]		\|[https://urldefense.com/v3/__https://archive.org/details/2010MoDotDDInterchangeRpt/mode/2up__;!!B-WfeG7HSw!ELjAx-rd5iNHaVjOMPnVDS0AI4xeYA_QfgfA88fEGLcagiXHLkxySaXZxgbWHRVBcXoir4nwKt7ymv3eZHLR-dDz7cBGd46gITsg3CW5$ Lessons, 2010]
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	\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012.pdf Performance Evaluation, 2011]		\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012.pdf Performance Evaluation, 2011]

Smithk at 20:19, 18 August 2020

2020-08-18T20:19:50Z

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	\|[[media:234.6 Safety Eval.pdf\|Safety Evaluation of Diverging Diamond Interchanges in Missouri, 2015]]		\|[[media:234.6 Safety Eval.pdf\|Safety Evaluation of Diverging Diamond Interchanges in Missouri, 2015]]
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	\|'''See also:''' [~~http~~://www.modot.~~gov~~/~~services/OR/byDate.htm Innovation Library~~]		\|'''See also:''' [https://www.modot.org/research-publications Research Publications]
	\|}		\|}

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	\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012_Sum.pdf Staff Summary, 2010]		\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012_Sum.pdf Staff Summary, 2010]
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	\|'''See also:''' [~~http~~://www.modot.~~gov~~/~~services/OR/byDate.htm Innovation Library~~]		\|'''See also:''' [https://www.modot.org/research-publications Research Publications]
	\|}		\|}

Smithk: updated links

2020-02-03T18:24:56Z

updated links

← Older revision		Revision as of 13:24, 3 February 2020
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	\|'''Diverging Diamond Interchange'''		\|'''Diverging Diamond Interchange'''
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	\|[~~http~~://~~library~~.modot.mo.gov/~~RDT~~/~~reports~~/~~UnNumbrd~~/~~or10021~~.pdf Lessons, 2010]		\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or10021_ReportNoApp.pdf Lessons, 2010]
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	\|[~~http~~://~~library~~.modot.mo.gov/~~RDT~~/~~reports~~/~~TRyy1013~~/or11012.pdf Performance Evaluation, 2011]		\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012.pdf Performance Evaluation, 2011]
	\|-		\|-
	\|[[media:234.6 Safety Eval.pdf\|Safety Evaluation of Diverging Diamond Interchanges in Missouri, 2015]]		\|[[media:234.6 Safety Eval.pdf\|Safety Evaluation of Diverging Diamond Interchanges in Missouri, 2015]]
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	\|'''Diverging Diamond Interchange'''		\|'''Diverging Diamond Interchange'''
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	\|[~~http~~://~~library~~.modot.mo.gov/~~RDT~~/~~reports~~/~~TRyy1013~~/~~orb10005~~.pdf Staff Summary, 2010]		\|[https://spexternal.modot.mo.gov/sites/cm/CORDT/or11012_Sum.pdf Staff Summary, 2010]
	\|-		\|-
	\|'''See also:''' [http://www.modot.gov/services/OR/byDate.htm Innovation Library]		\|'''See also:''' [http://www.modot.gov/services/OR/byDate.htm Innovation Library]

Smithk: /* 234.6.2.2.15 Pedestrians */

2019-04-26T15:49:02Z

234.6.2.2.15 Pedestrians

← Older revision		Revision as of 10:49, 26 April 2019
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	Design of the pedestrian facilities should be in accordance with [[:Category:642 Pedestrian Facilities\|EPG 642 Pedestrian Facilities]]. The width of the sidewalk is a minimum of 5 ft. if there is at least a 2 ft. separation from the curb and a minimum of 6 ft. wide if located adjacent to the curb. If bicycle traffic is anticipated to share the sidewalk, a minimum width of 8 ft. is required. Sidewalks wider than 8 ft. may be appropriate depending on the expected volumes of pedestrians and cyclists.		Design of the pedestrian facilities should be in accordance with [[:Category:642 Pedestrian Facilities\|EPG 642 Pedestrian Facilities]]. The width of the sidewalk is a minimum of 5 ft. if there is at least a 2 ft. separation from the curb and a minimum of 6 ft. wide if located adjacent to the curb. If bicycle traffic is anticipated to share the sidewalk, a minimum width of 8 ft. is required. Sidewalks wider than 8 ft. may be appropriate depending on the expected volumes of pedestrians and cyclists.

	All sidewalks must be compliant with the [~~http~~://www.access-board.gov/~~adaag~~/~~html~~/adaag~~.htm~~ Americans with Disabilities Act Accessibility Guidelines (ADAAG)] or the [http://www.access-board.gov/prowac/ Public Right of Way Accessibility Guidelines (PROWAG)]. Also, pedestrian signal components must comply with the [http://mutcd.fhwa.dot.gov/index.htm Manual on Uniform Traffic Control Devices (MUTCD)].		All sidewalks must be compliant with the [https://www.access-board.gov/guidelines-and-standards/buildings-and-sites/about-the-ada-standards/background/adaag Americans with Disabilities Act Accessibility Guidelines (ADAAG)] or the [http://www.access-board.gov/prowac/ Public Right of Way Accessibility Guidelines (PROWAG)]. Also, pedestrian signal components must comply with the [http://mutcd.fhwa.dot.gov/index.htm Manual on Uniform Traffic Control Devices (MUTCD)].

	Although standard curb ramps are an acceptable way to access a sidewalk on a channelizing island, it is strongly recommended at-grade cut throughs be used to provide positive guidance across sizable islands and the path through the island be as short and straight as possible so visually impaired persons do not become confused about the direction they are traveling.		Although standard curb ramps are an acceptable way to access a sidewalk on a channelizing island, it is strongly recommended at-grade cut throughs be used to provide positive guidance across sizable islands and the path through the island be as short and straight as possible so visually impaired persons do not become confused about the direction they are traveling.

Smithk: /* 234.6.7 Resources */ updated ADAAG link

2019-04-26T15:31:35Z

234.6.7 Resources: updated ADAAG link

← Older revision		Revision as of 10:31, 26 April 2019
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	5) [[Media:Green Book Fig 10-74.pdf\|AASHTO Green Book Figure 10-74, Typical Two-Lane Entrance Ramps]]		5) [[Media:Green Book Fig 10-74.pdf\|AASHTO Green Book Figure 10-74, Typical Two-Lane Entrance Ramps]]

	6) [~~http~~://www.access-board.gov/~~adaag~~/~~html~~/adaag~~.htm~~ ADAAG]		6) [https://www.access-board.gov/guidelines-and-standards/buildings-and-sites/about-the-ada-standards/background/adaag ADAAG]

	7) [http://www.access-board.gov/prowac/ PROWAC]		7) [http://www.access-board.gov/prowac/ PROWAC]

Smithk: /* 234.6.6 Public Involvement */ removed archaic link

2019-04-26T15:29:40Z

234.6.6 Public Involvement: removed archaic link

← Older revision		Revision as of 10:29, 26 April 2019
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	Traditional guidance on the need for public meetings and hearings still applies. However, consideration should be given to conducting additional public outreach at preliminary design and throughout the project development process in excess of the minimum warrants for a public hearing. These efforts serve to inform the public of anticipated construction impacts and operation of the facility. Modeling and simulations should be developed and used to augment [http://www.modot.mo.gov/springfield/major_projects/Greene/documents/I-44-Route13DDI.pdf traditional displays] to demonstrate the traffic movements and benefits. Experience has shown that an initial emphasis on the [http://www.youtube.com/user/modotvideo#p/search/0/NANacKPO0Q4 windshield-level experience] of driving a DDI is more effective in displaying the interchange layout than an [http://www.youtube.com/user/modotvideo#p/search/1/B5JtZMPTNAY aerial view] that can be confusing and may work against the goal of assuring the audience of the benefits.		Traditional guidance on the need for public meetings and hearings still applies. However, consideration should be given to conducting additional public outreach at preliminary design and throughout the project development process in excess of the minimum warrants for a public hearing. These efforts serve to inform the public of anticipated construction impacts and operation of the facility. Modeling and simulations should be developed and used to augment [http://www.modot.mo.gov/springfield/major_projects/Greene/documents/I-44-Route13DDI.pdf traditional displays] to demonstrate the traffic movements and benefits. Experience has shown that an initial emphasis on the [http://www.youtube.com/user/modotvideo#p/search/0/NANacKPO0Q4 windshield-level experience] of driving a DDI is more effective in displaying the interchange layout than an [http://www.youtube.com/user/modotvideo#p/search/1/B5JtZMPTNAY aerial view] that can be confusing and may work against the goal of assuring the audience of the benefits.

	~~[http://www.modot.mo.gov/kansascity/major_projects/Woods_Chapel_Diverging_Diamond.htm~~ Major project websites] are traditionally used for significant projects that are of public interest or that have large potential impacts. In the case of a DDI, a website serves as a particularly good opportunity to serve as a central repository for modeling, simulation and graphic visualizations that can be easily accessed by the public. Updates on status of the project, the timeline to milestones, dates for public hearings or meetings and other pertinent details can be collected and provided in one dedicated location. Any inquiries may be easily referred to this collection of data, which may aid in meeting the public’s expectation for involvement during project development and construction.		Major project websites are traditionally used for significant projects that are of public interest or that have large potential impacts. In the case of a DDI, a website serves as a particularly good opportunity to serve as a central repository for modeling, simulation and graphic visualizations that can be easily accessed by the public. Updates on status of the project, the timeline to milestones, dates for public hearings or meetings and other pertinent details can be collected and provided in one dedicated location. Any inquiries may be easily referred to this collection of data, which may aid in meeting the public’s expectation for involvement during project development and construction.

	[http://www.modot.mo.gov/facebook/index.htm Social media tools] are increasingly being used in similar fashion to major project websites. These types of sites assist in collecting public comments and providing less formal project information as the development and construction process continue. They also provide an opportunity to reach out to segments of the public who may not embrace the mainstream media for information.		[http://www.modot.mo.gov/facebook/index.htm Social media tools] are increasingly being used in similar fashion to major project websites. These types of sites assist in collecting public comments and providing less formal project information as the development and construction process continue. They also provide an opportunity to reach out to segments of the public who may not embrace the mainstream media for information.

Smithk: /* 234.6.6 Public Involvement */ removed archaic video

2019-03-13T12:48:11Z

234.6.6 Public Involvement: removed archaic video

← Older revision		Revision as of 07:48, 13 March 2019
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	Citizens expect and demand an active voice in their transportation decisions and implementing a DDI at a specific interchange is no exception. The innovative nature of the DDI concept and the public’s unfamiliarity with the design add to the complications when trying to foster a cooperative partnership with the public to use this solution in meeting a transportation need. On the other hand, as successes with DDIs are marketed and publicized, local stakeholders and the public could clamor for more implementation of the concept, especially considering its lower cost. A part of the public involvement effort could include thorough communication of situations where this interchange is not appropriate.		Citizens expect and demand an active voice in their transportation decisions and implementing a DDI at a specific interchange is no exception. The innovative nature of the DDI concept and the public’s unfamiliarity with the design add to the complications when trying to foster a cooperative partnership with the public to use this solution in meeting a transportation need. On the other hand, as successes with DDIs are marketed and publicized, local stakeholders and the public could clamor for more implementation of the concept, especially considering its lower cost. A part of the public involvement effort could include thorough communication of situations where this interchange is not appropriate.

	~~{\|style="padding: 0.3em; margin-left:10px; border:2px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="191px" align="right"~~
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	~~\|'''Video'''~~
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	~~\|[http://www.youtube.com/v/B5JtZMPTNAY&hl=en&fs=1&rel=0 '''What Does a DDI Look Like?''']~~
	\|}
	Traditional guidance on the need for public meetings and hearings still applies. However, consideration should be given to conducting additional public outreach at preliminary design and throughout the project development process in excess of the minimum warrants for a public hearing. These efforts serve to inform the public of anticipated construction impacts and operation of the facility. Modeling and simulations should be developed and used to augment [http://www.modot.mo.gov/springfield/major_projects/Greene/documents/I-44-Route13DDI.pdf traditional displays] to demonstrate the traffic movements and benefits. Experience has shown that an initial emphasis on the [http://www.youtube.com/user/modotvideo#p/search/0/NANacKPO0Q4 windshield-level experience] of driving a DDI is more effective in displaying the interchange layout than an [http://www.youtube.com/user/modotvideo#p/search/1/B5JtZMPTNAY aerial view] that can be confusing and may work against the goal of assuring the audience of the benefits.		Traditional guidance on the need for public meetings and hearings still applies. However, consideration should be given to conducting additional public outreach at preliminary design and throughout the project development process in excess of the minimum warrants for a public hearing. These efforts serve to inform the public of anticipated construction impacts and operation of the facility. Modeling and simulations should be developed and used to augment [http://www.modot.mo.gov/springfield/major_projects/Greene/documents/I-44-Route13DDI.pdf traditional displays] to demonstrate the traffic movements and benefits. Experience has shown that an initial emphasis on the [http://www.youtube.com/user/modotvideo#p/search/0/NANacKPO0Q4 windshield-level experience] of driving a DDI is more effective in displaying the interchange layout than an [http://www.youtube.com/user/modotvideo#p/search/1/B5JtZMPTNAY aerial view] that can be confusing and may work against the goal of assuring the audience of the benefits.

Smithk: /* 234.6.2.1.1 Modeling/Simulation */

2019-03-13T12:45:29Z

234.6.2.1.1 Modeling/Simulation

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	====234.6.2.1.1 Modeling/Simulation====		====234.6.2.1.1 Modeling/Simulation====

	An operational analysis (traffic study) should be conducted whenever a DDI is considered. Operational measures such as [[902.12 Glossary#Level of Service (LOS)\|Level of Service(LOS)]], delay and capacity can be used to compare the operational characteristics of a DDI with other types of interchanges, such as traditional diamonds or SPUIs. The operational analysis can also be used to determine the number of lanes and the configuration needed for the DDI to operate acceptably.		An operational analysis (traffic study) should be conducted whenever a DDI is considered. Operational measures such as [[902.12 Glossary#Level of Service (LOS)\|Level of Service (LOS)]], delay and capacity can be used to compare the operational characteristics of a DDI with other types of interchanges, such as traditional diamonds or SPUIs. The operational analysis can also be used to determine the number of lanes and the configuration needed for the DDI to operate acceptably.

	Generally, micro-simulation modeling, such as VISSIM, is the preferred method for analyzing a DDI. In some situations, such as at isolated interchange locations and at low-volume locations, traditional ''Highway Capacity Manual'' (HCM) methods can produce reasonable results. Any nearby intersections, less than one-half mile from the interchange, should be included in the model. In addition to providing operational measures, micro-simulation models can be used to create animations. These animations are commonly used to help the public understand the DDI concept and the benefits of using a DDI at a particular location.		Generally, micro-simulation modeling, such as VISSIM, is the preferred method for analyzing a DDI. In some situations, such as at isolated interchange locations and at low-volume locations, traditional ''Highway Capacity Manual'' (HCM) methods can produce reasonable results. Any nearby intersections, less than one-half mile from the interchange, should be included in the model. In addition to providing operational measures, micro-simulation models can be used to create animations. These animations are commonly used to help the public understand the DDI concept and the benefits of using a DDI at a particular location.

Smithk at 12:16, 13 March 2019

2019-03-13T12:16:18Z

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	{\| style="margin: 1em auto 1em auto" align="right"		{\| style="margin: 1em auto 1em auto" align="right"
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	\|colspan="2"\|[[image:234.6.jpg\|right\|450px\|thumb\|<center>'''The first [~~http~~://www.youtube.com/v~~/B5JtZMPTNAY&hl=en&fs=1&rel~~=0 DDI] in the nation opened to traffic June 21, 2009, in Springfield and has been a huge success. The interchange was chosen as one of the best new engineering innovations of 2009 by ''Popular Science'' magazine. The Springfield DDI also earned an AASHTO award and a Governor’s Award for Quality and Productivity.'''</center>]]		\|colspan="2"\|[[image:234.6.jpg\|right\|450px\|thumb\|<center>'''The first [https://www.youtube.com/watch?v=wYd9ikEoKqs DDI] in the nation opened to traffic June 21, 2009, in Springfield and has been a huge success. The interchange was chosen as one of the best new engineering innovations of 2009 by ''Popular Science'' magazine. The Springfield DDI also earned an AASHTO award and a Governor’s Award for Quality and Productivity.'''</center>]]
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	\|[[image:234.6 sign.png\|right\|333px]]\|\|[[image:234.6 award.jpg\|right\|94px]]		\|[[image:234.6 sign.png\|right\|333px]]\|\|[[image:234.6 award.jpg\|right\|94px]]

Smithk: /* 234.6.2.2.6 Ramp and Preliminary Plan Criteria */ Per EPG, updated terminology to current "federal involvement" instead of "Full Oversight"

2015-12-08T16:14:51Z

234.6.2.2.6 Ramp and Preliminary Plan Criteria: Per EPG, updated terminology to current "federal involvement" instead of "Full Oversight"

← Older revision		Revision as of 11:14, 8 December 2015
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	Typically, ramp base lines are always equated to the survey centerline and other ramp base line intersection points or the cross route centerline intersection point. The equations include offsets and intersection angles. For ease of identification, interchange ramps are numbered. Ramp details can be found on [http://www.modot.mo.gov/business/standards_and_specs/documents/20340.pdf Standard Plan 203.40]. The district approves the geometric layout of a DDI from the schematic drawing shown on the preliminary plan.		Typically, ramp base lines are always equated to the survey centerline and other ramp base line intersection points or the cross route centerline intersection point. The equations include offsets and intersection angles. For ease of identification, interchange ramps are numbered. Ramp details can be found on [http://www.modot.mo.gov/business/standards_and_specs/documents/20340.pdf Standard Plan 203.40]. The district approves the geometric layout of a DDI from the schematic drawing shown on the preliminary plan.

	At this preliminary plan stage, interchange geometric sheets are submitted to the Design Division for review and comments. Plans are also submitted for all ~~full oversight~~ projects for ~~Federal Highway Administration (FHWA) approval~~.		At this preliminary plan stage, interchange geometric sheets are submitted to the Design Division for review and comments. Plans are also submitted to FHWA for approval on all projects designated for federal involvement for preliminary plans on the PODI Matrix.

	====234.6.2.2.7 Sight Distance====		====234.6.2.2.7 Sight Distance====