Roadways: Interchange/Intersection - Revision history

Mnemphos at 17:13, 11 December 2024

2024-12-11T17:13:33Z

Mnemphos at 14:05, 5 June 2024

2024-06-05T14:05:53Z

Mnemphos: /* At – Grade Intersections */

2016-11-04T15:08:43Z

‎At – Grade Intersections

Mnemphos at 15:03, 4 November 2016

2016-11-04T15:03:53Z

Mnemphos: /* At – Grade Intersections */

2016-11-04T14:57:45Z

‎At – Grade Intersections

Mnemphos: /* At – Grade Intersections */

2016-11-04T14:56:41Z

‎At – Grade Intersections

Mnemphos at 20:14, 1 November 2016

2016-11-01T20:14:23Z

Mnemphos at 20:14, 1 November 2016

2016-11-01T20:14:09Z

Mnemphos at 17:01, 1 November 2016

2016-11-01T17:01:29Z

Mnemphos at 15:30, 1 November 2016

2016-11-01T15:30:39Z

← Older revision		Revision as of 17:13, 11 December 2024
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	*[[Practical Design Implementation Guidance\|Practical Design Implementation Guidance]]		*[[Practical Design Implementation Guidance\|Practical Design Implementation Guidance]]
−	~~[[Category:Secure]]~~

← Older revision		Revision as of 14:05, 5 June 2024
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	*[[Practical Design Implementation Guidance\|Practical Design Implementation Guidance]]		*[[Practical Design Implementation Guidance\|Practical Design Implementation Guidance]]
		+	[[Category:Secure]]

@@ Line 25: / Line 25: @@
 *Uncontrolled Intersections
-Signalization entails significant costs and ongoing maintenance and should be implemented only when necessary.  Signalization is discouraged when safety and operational concerns at uncontrolled intersections may be addressed by other treatments such as implementing a yield or stop condition, signing, roadway lighting, or minor geometric changes.  Signal warrants should be met before considering a traffic signal as a viable option; however, meeting signal warrants does not mean that a signal should be installed.  A traffic study needs to be completed to evaluate each alternative to determine which one would provide the most benefit.  In some cases, even if a signal is warranted, other treatments such as roundabouts or no-build may provide the greatest benefit/cost.
+Signalization entails significant costs and ongoing maintenance and should be implemented only when necessary.  Signalization is discouraged when safety and operational concerns at uncontrolled intersections may be addressed by other treatments such as implementing a yield or stop condition, signing, roadway lighting, or minor geometric changes.  Signal warrants should be met before considering a traffic signal as a viable option; however, meeting signal warrants does not mean that a signal should be installed.  A traffic study needs to be completed to evaluate each alternative to determine which one would provide the most benefit.  In some cases, even if a signal is warranted, other treatments such as [http://safety.fhwa.dot.gov/intersection/innovative/roundabouts/fhwasa10006/ roundabouts] or no-build may provide the greatest benefit/cost.
 *Signalized Intersections
-Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.    Some examples of innovative intersection designs may include Continuous Flow Intersections, Michigan U-Turns, [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], [http://safety.fhwa.dot.gov/intersection/innovative/others/casestudies/fhwasa09016/ Maryland T’s], etc.  Impacts to all roadway users who will use the facilities should be considered.
+Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.    Some examples of innovative intersection designs may include [http://www.fhwa.dot.gov/publications/research/safety/09057/index.cfm Continuous Flow Intersections], [http://www.fhwa.dot.gov/publications/research/safety/09057/index.cfm Michigan U-Turns], [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], [http://safety.fhwa.dot.gov/intersection/innovative/others/casestudies/fhwasa09016/ Maryland T’s], etc.  Impacts to all roadway users who will use the facilities should be considered.
 ==Grade – Separated Interchanges==

@@ Line 7: / Line 7: @@
 | colspan="3" |
 =Primary Guidance=
-*At-Grade Intersections and Grade Separated Interchanges identified for improvement should go through a needs evaluation process to determine specific safety, capacity, and operational deficiencies to be addressed.
+*At-Grade Intersections and Grade Separated Interchanges identified for improvement should go through a needs evaluation process to determine specific safety, capacity, and operational deficiencies to be addressed
-*Safety improvements should be addressed by reducing or eliminating problematic conflict points. Capacity needs should be based on traffic analysis in the design year, not to exceed the 20 year forecast.
+*Address safety improvements by reducing or eliminating problematic conflict points
-*Prior to proposing new signals, interchanges, or major geometric changes, designers should evaluate operational and minor geometric improvements that could address identified needs. Innovative intersection treatments that may provide needed improvements while minimizing impacts and costs should be considered.
+*Based capacity needs on traffic analysis in the design year, not to exceed the 20 year forecast
-*Intersection and interchange spacing guidelines balance access and mobility for a given roadway functional classification and context. Signal warrants should be met prior to installing new traffic signals. At-grade intersection treatments, including innovative designs, should be fully considered before selecting grade separation on an uncontrolled or partially access controlled roadway.
+*Prior to proposing new signals, interchanges, or major geometric changes, evaluate operational and minor geometric improvements that could address identified needs as innovative intersection treatments may provide needed improvements while minimizing impacts and costs
 |-
@@ Line 19: / Line 23: @@
 ==At – Grade Intersections==
 *Uncontrolled Intersections
-Signalization entails significant costs and ongoing maintenance and should be implemented only when necessary.  Signalization is discouraged when safety and operational concerns at uncontrolled intersections may be addressed by other treatments such as implementing a yield or stop condition, signing, roadway lighting, or minor geometric changes.  If needs call for implementing a traffic signal, perform a signal warrant analysis.  In some cases, even if a signal is warranted, other treatments, such as roundabouts, can be considered to help control traffic movements.
+Signalization entails significant costs and ongoing maintenance and should be implemented only when necessary.  Signalization is discouraged when safety and operational concerns at uncontrolled intersections may be addressed by other treatments such as implementing a yield or stop condition, signing, roadway lighting, or minor geometric changes.  Signal warrants should be met before considering a traffic signal as a viable option; however, meeting signal warrants does not mean that a signal should be installed.  A traffic study needs to be completed to evaluate each alternative to determine which one would provide the most benefit.  In some cases, even if a signal is warranted, other treatments such as roundabouts or no-build may provide the greatest benefit/cost.
 *Signalized Intersections
-Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.  Some examples of innovative intersection designs may include Continuous Flow Intersections, Michigan U-Turns, [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], [http://safety.fhwa.dot.gov/intersection/innovative/others/casestudies/fhwasa09016/ Maryland T’s], etc.  Impacts to all roadway users who will use the facilities should be considered.
+Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.    Some examples of innovative intersection designs may include Continuous Flow Intersections, Michigan U-Turns, [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], [http://safety.fhwa.dot.gov/intersection/innovative/others/casestudies/fhwasa09016/ Maryland T’s], etc.  Impacts to all roadway users who will use the facilities should be considered.
 ==Grade – Separated Interchanges==
 *Existing Interchanges
 Consider options to maintain elements of the existing interchange and replace only those elements needing improvement before considering full reconstruction options.  Innovative solutions such as a Diverging Diamond Interchange or ramp metering can be considered to address needs while minimizing impacts and costs.
 *Interchange Spacing
 New interchanges should be appropriately spaced to eliminate conflict with existing interchanges within the corridor.

@@ Line 22: / Line 22: @@
 Signalization entails significant costs and ongoing maintenance and should be implemented only when necessary.  Signalization is discouraged when safety and operational concerns at uncontrolled intersections may be addressed by other treatments such as implementing a yield or stop condition, signing, roadway lighting, or minor geometric changes.  If needs call for implementing a traffic signal, perform a signal warrant analysis.  In some cases, even if a signal is warranted, other treatments, such as roundabouts, can be considered to help control traffic movements.
 *Signalized Intersections
-Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.  Some examples of innovative intersection designs may include Continuous Flow Intersections, Michigan U-Turns, [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], Maryland T’s, etc.  Impacts to all roadway users who will use the facilities should be considered.
+Existing traffic signals should be evaluated to see if timing can be optimized for specific locations, or if within a corridor, multiple signals may need to be coordinated in order to improve performance.  Network solutions or innovative at-grade intersection designs should be considered when appropriate to help reduce the cost of traditional geometric and operational solutions.  Some examples of innovative intersection designs may include Continuous Flow Intersections, Michigan U-Turns, [http://www.fhwa.dot.gov/publications/research/safety/09059/index.cfm J-Turns], [http://safety.fhwa.dot.gov/intersection/innovative/others/casestudies/fhwasa09016/ Maryland T’s], etc.  Impacts to all roadway users who will use the facilities should be considered.
 ==Grade – Separated Interchanges==

@@ Line 2: / Line 2: @@
 | colspan="3" |
-'''Interchange/Intersection''''
+'''Interchange/Intersection'''
 |-

@@ Line 1: / Line 1: @@
 {| class="wikitable"
 | colspan="3" |
-'''Construction Staging'''
 |-
@@ Line 19: / Line 19: @@
 ==At – Grade Intersections==
 ==Grade – Separated Interchanges==
-*Grade Separating an Existing Intersection – Grade separation should be selected when conflicting high traffic volumes exceed those that can be handled efficiently and safely with an at-grade intersection. Occasionally, it may be appropriate to grade separate an intersection with a disproportionate rate of crashes that is not likely to be reduced through at-grade improvements, or an intersection on a corridor transitioning to full access control.
+*Grade Separating an Existing Intersection
-*Existing Interchanges - The designer should consider options to maintain elements of the existing interchange and replace only those elements needing improvement before considering full reconstruction options. Innovative solutions such as a Diverging Diamond Interchange or ramp metering can be considered to address needs while minimizing impacts and costs.
+Grade separation should be selected when conflicting high traffic volumes exceed those that can be handled efficiently and safely with an at-grade intersection.  Occasionally, it may be appropriate to grade separate an intersection with a disproportionate rate of crashes that is not likely to be reduced through at-grade improvements, or an intersection on a corridor transitioning to full access control.
-*Interchange Spacing – New interchanges should be appropriately spaced to eliminate conflict with existing interchanges within the corridor.
+*Existing Interchanges

@@ Line 16: / Line 16: @@
 =Discussion=
-[[File:LOS Graphic.jpg|650px|right]]
 ==At – Grade Intersections==