User:Ldriveskier/Contraflow Configuration View history

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Draw a segment for the length of the crossover (no connections). Place it next to and parallel to the lane going the opposite direction, following curves
[[File:Contraflow_sign.png|right|thumb|250px]]'''Contraflow configuration''' is necessary when normal one-way traffic on a divided road is diverted across the median and then runs in a contraflow manner respective to the traffic direction on that side of the median.
* Set to Freeway
* Set to one-way
* Set appropriate speed limit
* Match elevation to segment being mirrored (may need to cut for elevation changes, watch especially around exits and underpasses/overpasses)


[[File:CrossoverParallel.JPG|thumbnail|center]]
Contraflow configuration and new traffic patterns can be quite varied depending on circumstances that might necessitate their usage. Therefore, editors should consult their respective Large Area Managers or State Managers before beginning the process for a [[scheduled reconfiguration]] involving contraflow.


At the end of the crossover, merge traffic following entrance ramp geometry guidance.
== When to map contraflow ==
[[File:CrossoverMUTCD.png|right|thumb|250px]]
=== Construction ===
For long term construction projects, one or more lanes may be diverted across the median to occupy lanes that are normally used for traffic traveling in the opposite direction. It is especially important to map a contraflow when these lanes may bypass one or more exits that would normally be accessible from that route. If the distance between the two opposing lanes is too much, not mapping the contraflow lanes can result in Waze navigation thinking the user is driving against traffic and behave unpredictably. If this is the case, they should be mapped even if there is no difference in navigational guidance.


[[File:CrossoverEnd.JPG|thumbnail|center]]
=== Hurricane evacuation ===
''Need verbiage here''


At beginning of the crossover, connect the segment following exit ramp geometry guidance.
== How to map contraflow ==


[[File:CrossoverBegin.jpg|thumbnail|center]]
=== Draw contraflow segment ===
# Draw a new segment spanning the length of the new contraflow section.  This new segment should remain unconnected from any existing segments for now.
# Draw the new contraflow segment next to the existing opposing direction segment that this new segment will serve as a contraflow lane against.
#* Adjust the geometry nodes on the new segment so that the contraflow segments are parallel to and close to the appropriate segments.[[File:CrossoverParallel.JPG|thumbnail|center|600x600px]]
# Set appropriate attributes for the new contraflow segment:
#* <u>Name</u>:  Should match the existing road it is being split off from.
#* <u>Road type</u>:  Match the existing road type.
#* <u>Direction</u>:  One-way (A->B or B->A, depending on how segment was drawn)
#* <u>Speed Limit</u>:  For contraflow sections, note that there may be different speed limits based on direction of travel through the reconfigured area. 
#* <u>Elevation</u>:  Match the elevation of the newly drawn segment to the contraflow segment being mirrored.  This may require cutting the newly drawn segment for elevation changes, particularly around exits & underpasses/overpasses.


Consider adding wayfinders to match signage or provide guidance. For example,
=== Connect contraflow to existing segments ===
# Connect the contraflow segment for the crossover at the end of the reconfiguration, following the [[Junction_Style_Guide/Interchange#Ramp_geometry_and_complexity|entrance ramp geometry guidance]] for drawing the merge angle.  [[File:CrossoverEnd.JPG|thumbnail|center|600x600px]]
# Connect the contraflow segment for the crossover at the beginning of the reconfiguration, following the segment following [[Junction_Style_Guide/Interchange#Ramp_geometry_and_complexity|exit ramp geometry guidance]].
#* Consider that there will likely be a solid white line separating lanes before the actual lane crosses over into oncoming lanes, so the new lane may be parallel and next to the existing lane before being diverted to the contraflow side.
[[File:CrossoverBegin.jpg|thumbnail|center|800x800px]]
 
=== Add wayfinders for contraflow lanes ===
After connecting the contraflow segments, consider adding [[wayfinder]]s to match signage or provide guidance. It is important to make it clear when a choice may bypass exits or when a choice is the only route to a certain exit or all exits. For example,
* I-80 W only / Thru traffic
* I-80 W only / Thru traffic
* I-80 W / I-480 / SR-14 / All Exits
* I-80 W / to exit 187 / I-480 / SR-14
* Note: be sure to remove alt-names to avoid BC
* I-80 W / All Exits
* Consider that there will likely be a SWL separating lanes before the actual lane crosses over into oncoming lanes.
[[File:CrossoverWayfinder.JPG|thumbnail|center|600x600px]]
 
*  NOTE: If a wayfinder is part of a scheduled reconfiguration, ensure the wayfinder for the existing lanes stays as BC until the traffic switch for the contraflow becomes active to avoid confusion.
[[File:CrossoverWayfinder.JPG|thumbnail|center]]
__FORCETOC__
 
Note: I prefer to draw the whole thing first (before even asking for a downlock), attach the end second, then attach the beginning. If I get pulled away in the middle, I'd rather have a random segment laying around that isn't attached to anything important.
 
test

Latest revision as of 16:49, 20 November 2017

Contraflow configuration is necessary when normal one-way traffic on a divided road is diverted across the median and then runs in a contraflow manner respective to the traffic direction on that side of the median.

Contraflow configuration and new traffic patterns can be quite varied depending on circumstances that might necessitate their usage. Therefore, editors should consult their respective Large Area Managers or State Managers before beginning the process for a scheduled reconfiguration involving contraflow.

When to map contraflow

Construction

For long term construction projects, one or more lanes may be diverted across the median to occupy lanes that are normally used for traffic traveling in the opposite direction. It is especially important to map a contraflow when these lanes may bypass one or more exits that would normally be accessible from that route. If the distance between the two opposing lanes is too much, not mapping the contraflow lanes can result in Waze navigation thinking the user is driving against traffic and behave unpredictably. If this is the case, they should be mapped even if there is no difference in navigational guidance.

Hurricane evacuation

Need verbiage here

How to map contraflow

Draw contraflow segment

  1. Draw a new segment spanning the length of the new contraflow section. This new segment should remain unconnected from any existing segments for now.
  2. Draw the new contraflow segment next to the existing opposing direction segment that this new segment will serve as a contraflow lane against.
    • Adjust the geometry nodes on the new segment so that the contraflow segments are parallel to and close to the appropriate segments.
  3. Set appropriate attributes for the new contraflow segment:
    • Name: Should match the existing road it is being split off from.
    • Road type: Match the existing road type.
    • Direction: One-way (A->B or B->A, depending on how segment was drawn)
    • Speed Limit: For contraflow sections, note that there may be different speed limits based on direction of travel through the reconfigured area.
    • Elevation: Match the elevation of the newly drawn segment to the contraflow segment being mirrored. This may require cutting the newly drawn segment for elevation changes, particularly around exits & underpasses/overpasses.

Connect contraflow to existing segments

  1. Connect the contraflow segment for the crossover at the end of the reconfiguration, following the entrance ramp geometry guidance for drawing the merge angle.
  2. Connect the contraflow segment for the crossover at the beginning of the reconfiguration, following the segment following exit ramp geometry guidance.
    • Consider that there will likely be a solid white line separating lanes before the actual lane crosses over into oncoming lanes, so the new lane may be parallel and next to the existing lane before being diverted to the contraflow side.

Add wayfinders for contraflow lanes

After connecting the contraflow segments, consider adding wayfinders to match signage or provide guidance. It is important to make it clear when a choice may bypass exits or when a choice is the only route to a certain exit or all exits. For example,

  • I-80 W only / Thru traffic
  • I-80 W / to exit 187 / I-480 / SR-14
  • I-80 W / All Exits
  •  NOTE: If a wayfinder is part of a scheduled reconfiguration, ensure the wayfinder for the existing lanes stays as BC until the traffic switch for the contraflow becomes active to avoid confusion.