Category:617 Traffic Barrier - Revision history

Hoskir: updated per RR3850

2024-05-06T20:18:45Z

updated per RR3850

← Older revision		Revision as of 15:18, 6 May 2024
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	[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [https://www.modot.org/media/16893 Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [https://www.modot.org/media/16893 Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].

	~~[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]~~

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. ~~Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier.~~ Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

Smithk at 12:57, 2 July 2019

2019-07-02T12:57:14Z

← Older revision		Revision as of 07:57, 2 July 2019
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	[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [~~http~~://modot.~~mo.gov~~/~~business~~/~~standards_and_specs/documents/61710.pdf~~ Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [https://www.modot.org/media/16893 Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].

	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

Smithk at 15:48, 11 June 2019

2019-06-11T15:48:24Z

← Older revision		Revision as of 10:48, 11 June 2019
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	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:~~606.1~~ Warrant for Median Barriers.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

Smithk at 14:52, 11 June 2019

2019-06-11T14:52:39Z

← Older revision		Revision as of 09:52, 11 June 2019
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	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[~~media~~:~~231_Warrant_for_Median_Barriers~~.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:606.1 Warrant for Median Barriers.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

Smithk at 14:23, 28 September 2018

2018-09-28T14:23:46Z

← Older revision		Revision as of 09:23, 28 September 2018
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	The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].		The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].

	Concrete barrier and Type B guardrail are placed on a flush median. [[media:231_Warrant_for_Median_Barriers.pdf\|Warrants for median barrier]] are used to determine the locations for which these two types of barrier are to be provided. Concrete barrier is generally limited to the high volume roadways with narrow width medians. When concrete barrier is used, Type C (and Type D, as required) is the preferred configuration for new construction. Type A (and Type B, as required) is only to be used for new construction projects in a retrofit condition or to “tie in” to existing Type A concrete barrier, which exists on adjoining sections of roadway. An approved crash cushion or sloped end crashworthy end terminal is the required end treatment for concrete barriers. A barrier height transition is not to be used in locations where the posted speed limit is greater than 35 mph. Where height transitions are used, they are to be located as far as practicable from the traffic lanes, and if possible, the lead end flared outside the clear zone. Concrete barrier details and barrier height transitions are shown in [~~http~~://www.modot.~~mo.gov/business/standards_and_specs~~/~~documents~~/~~61710.pdf~~ Standard Plan 617.10]. The distance between the left hand edge of the lane next to the median and the face of the concrete median barrier is not to be more than 15 ft. (4.5 m).		Concrete barrier and Type B guardrail are placed on a flush median. [[media:231_Warrant_for_Median_Barriers.pdf\|Warrants for median barrier]] are used to determine the locations for which these two types of barrier are to be provided. Concrete barrier is generally limited to the high volume roadways with narrow width medians. When concrete barrier is used, Type C (and Type D, as required) is the preferred configuration for new construction. Type A (and Type B, as required) is only to be used for new construction projects in a retrofit condition or to “tie in” to existing Type A concrete barrier, which exists on adjoining sections of roadway. An approved crash cushion or sloped end crashworthy end terminal is the required end treatment for concrete barriers. A barrier height transition is not to be used in locations where the posted speed limit is greater than 35 mph. Where height transitions are used, they are to be located as far as practicable from the traffic lanes, and if possible, the lead end flared outside the clear zone. Concrete barrier details and barrier height transitions are shown in [https://www.modot.org/media/16893 Standard Plan 617.10]. The distance between the left hand edge of the lane next to the median and the face of the concrete median barrier is not to be more than 15 ft. (4.5 m).

	{\|style="padding: 0.3em; margin-right:5px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="160px" align="left"		{\|style="padding: 0.3em; margin-right:5px; border:1px solid #a9a9a9; text-align:center; font-size: 95%; background:#f5f5f5" width="160px" align="left"

Smithk: Per BR, minor correction

2016-09-22T17:36:13Z

Per BR, minor correction

← Older revision		Revision as of 12:36, 22 September 2016
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	[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard ~~Drawing~~ 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].

	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

Smithk: updated links

2016-06-09T15:16:20Z

updated links

← Older revision		Revision as of 10:16, 9 June 2016
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	\|}		\|}

	[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://modot.~~mo.gov~~/business/standards_and_specs/~~Sec0617~~.pdf Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard Drawing 617.10] and [http://modot.~~mo.gov~~/business/standards_and_specs/~~Sec1065~~.pdf Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard Drawing 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].

	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

Smithk: updated link

2012-01-19T16:04:02Z

updated link

← Older revision		Revision as of 11:04, 19 January 2012
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	\|}		\|}

	[[620.4 Delineators (MUTCD Chapter 3D)#620.4.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://modot.mo.gov/business/standards_and_specs/Sec0617.pdf Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard Drawing 617.10] and [http://modot.mo.gov/business/standards_and_specs/Sec1065.pdf Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://modot.mo.gov/business/standards_and_specs/Sec0617.pdf Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [http://modot.mo.gov/business/standards_and_specs/documents/61710.pdf Standard Drawing 617.10] and [http://modot.mo.gov/business/standards_and_specs/Sec1065.pdf Sec 1065].

	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

Smithk: new photo

2011-05-02T19:21:03Z

new photo

← Older revision		Revision as of 14:21, 2 May 2011
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			[[image:617 May 2011.jpg\|right\|425px]]
	[[image:617 ~~Concrete Traffic Barrier~~.jpg\|right\|~~350px~~]]



	The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].		The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].

Smithk: removed Key Points

2008-11-13T17:29:11Z

removed Key Points

← Older revision		Revision as of 12:29, 13 November 2008
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	~~{\|border="4"~~
	~~\|-style="background:yellow"~~
	~~\|'''[[Key Points 617 Traffic Barrier\|Key Points]]'''~~
	\|}

	[[image:617 Concrete Traffic Barrier.jpg\|right\|350px]]		[[image:617 Concrete Traffic Barrier.jpg\|right\|350px]]

← Older revision		Revision as of 15:18, 6 May 2024
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	[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [https://www.modot.org/media/16893 Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].		[[620.5 Delineators (MUTCD Chapter 3F)#620.5.6 Barrier Wall Delineation\|Permanent barrier wall and bridge barrier wall delineation]] shall be in accordance with [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=9 Sec 617.30 of the Standard Specifications]. The design of barrier wall delineators shall be in acordance with [https://www.modot.org/media/16893 Standard Plan 617.10] and [http://www.modot.org/business/standards_and_specs/SpecbookEPG.pdf#page=14 Sec 1065].

	~~[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]~~

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. ~~Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier.~~ Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

← Older revision		Revision as of 10:48, 11 June 2019
Line 16:		Line 16:
	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:~~606.1~~ Warrant for Median Barriers.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:231 Warrant for Median Barriers a.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

← Older revision		Revision as of 09:52, 11 June 2019
Line 16:		Line 16:
	[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]		[[image:617 GuardCableRepair.jpg\|left\|200px\|thumb\|<center>'''Installing low-tension guard cable'''</center>]]

	[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[~~media~~:~~231_Warrant_for_Median_Barriers~~.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.		[[231.1 Median Width\|Medians wider than 36 ft.]] are sufficiently wide to satisfy clear zone requirements, thus making the provision of median barrier (refer to [[Media:606.1 Warrant for Median Barriers.pdf\|warrants for median barrier]]) optional. While the provision of a concrete barrier or Type B guardrail may not be required at these locations, a three-strand guard cable may be desirable.

	Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.		Although [[606.2 Guard Cable\|the cable system]] is relatively inexpensive to install, when compared with a concrete barrier or Type B guardrail system, and performs well when hit, it must be repaired after each hit to maintain its effectiveness. Especially for low-tension guard cable, this repair must be done as quickly as possible after a hit to ensure the effectiveness of the barrier. Consequently, its use in areas where it is likely to be frequently hit is not recommended. In these situations other types of median barrier are to be considered.

	[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.		[[606.1 Guardrail\|Guardrail]] or concrete barrier blunt ends located on either side of a two-way roadway or on the guardrail approach end of dual lane facilities must be replaced with an approved crashworthy end terminal even if the project covers only rehabilitation of the roadway in one direction.

← Older revision		Revision as of 09:23, 28 September 2018
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	The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].		The three types of median barrier used by MoDOT include concrete barrier, Type B [[606.1 Guardrail\|guardrail]], and [[606.2 Guard Cable\|guard cable]]. This article primarily deals with concrete barrier. There are many aspects to be considered when inspecting construction quality and this article also provides [[617.2 Construction Inspection Guidelines for Sec 617\|construction inspection guidelines]], [[617.3 Material Inspection for Sec 617\|material inspection guidelines]] as well as [[617.5 Maintenance Planning Guidelines for Concrete Traffic Barriers\|Maintenance planning guidelines for concrete traffic barriers]].

	Concrete barrier and Type B guardrail are placed on a flush median. [[media:231_Warrant_for_Median_Barriers.pdf\|Warrants for median barrier]] are used to determine the locations for which these two types of barrier are to be provided. Concrete barrier is generally limited to the high volume roadways with narrow width medians. When concrete barrier is used, Type C (and Type D, as required) is the preferred configuration for new construction. Type A (and Type B, as required) is only to be used for new construction projects in a retrofit condition or to “tie in” to existing Type A concrete barrier, which exists on adjoining sections of roadway. An approved crash cushion or sloped end crashworthy end terminal is the required end treatment for concrete barriers. A barrier height transition is not to be used in locations where the posted speed limit is greater than 35 mph. Where height transitions are used, they are to be located as far as practicable from the traffic lanes, and if possible, the lead end flared outside the clear zone. Concrete barrier details and barrier height transitions are shown in [~~http~~://www.modot.~~mo.gov/business/standards_and_specs~~/~~documents~~/~~61710.pdf~~ Standard Plan 617.10]. The distance between the left hand edge of the lane next to the median and the face of the concrete median barrier is not to be more than 15 ft. (4.5 m).		Concrete barrier and Type B guardrail are placed on a flush median. [[media:231_Warrant_for_Median_Barriers.pdf\|Warrants for median barrier]] are used to determine the locations for which these two types of barrier are to be provided. Concrete barrier is generally limited to the high volume roadways with narrow width medians. When concrete barrier is used, Type C (and Type D, as required) is the preferred configuration for new construction. Type A (and Type B, as required) is only to be used for new construction projects in a retrofit condition or to “tie in” to existing Type A concrete barrier, which exists on adjoining sections of roadway. An approved crash cushion or sloped end crashworthy end terminal is the required end treatment for concrete barriers. A barrier height transition is not to be used in locations where the posted speed limit is greater than 35 mph. Where height transitions are used, they are to be located as far as practicable from the traffic lanes, and if possible, the lead end flared outside the clear zone. Concrete barrier details and barrier height transitions are shown in [https://www.modot.org/media/16893 Standard Plan 617.10]. The distance between the left hand edge of the lane next to the median and the face of the concrete median barrier is not to be more than 15 ft. (4.5 m).

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