Difference between revisions of "Roundabout"

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==What is a roundabout and what is not==
 
==What is a roundabout and what is not==
Most parts of Europe use roundabouts regularly in intersections, while in the United States they are generally less common. In general when there is a clear roundabout in imagery, it is best to have it mapped as a roundabout in the road layer. There are a few cases that should '''not''' be mapped as roundabouts.
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In general when there is a clear roundabout in imagery, it is best to have it mapped as a roundabout in the road layer. There are a few cases that should '''not''' be mapped as roundabouts.
  
 
{| class="wikitable unsortable" border="1"
 
{| class="wikitable unsortable" border="1"
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|A single road segment leading to a cul-de-sac should be drawn as a [[Junction_Style_Guide#Dead_Ends|dead end]]. With very large roads it might be advisable to create a [[Junction_Style_Guide#Loops|three-segment loop]] but not a roundabout.
 
|A single road segment leading to a cul-de-sac should be drawn as a [[Junction_Style_Guide#Dead_Ends|dead end]]. With very large roads it might be advisable to create a [[Junction_Style_Guide#Loops|three-segment loop]] but not a roundabout.
 
|[[Image:Jct cul-de-sac island ex.png|100px]]
 
|[[Image:Jct cul-de-sac island ex.png|100px]]
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|-
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|[https://safety.fhwa.dot.gov/saferjourney1/library/countermeasures/27.htm Small traffic-calming circles] are usually not drawn as roundabouts, especially if they do not increase the size of the intersection greater than that of a simple four-way intersection, have no roundabout signs or yield signs and have stop signs on at least one approach. Check with local leadership on how to map traffic circles.
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|[[Image:TrafficCircleSquare.png|100px]]
 
|-  
 
|-  
 
|}
 
|}
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==Creation from an intersection==
 
==Creation from an intersection==
Oftentimes, when streets become more congested, planners will install a roundabout to get traffic to flow more freely. This section shows the steps to get from an existing intersection to a new roundabout.
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[[File:AdjustforRA.png|300x300px|right|alt=]] First, move the junction to the center of the roundabout. Click and drag the junction to where it should be. We also need to adjust the incoming segments so that they align with the roads leading into the roundabout. When roundabouts are built at existing intersections, the approaching segments are usually realigned for drivers to reach optimal speeds when entering and exiting the roundabout and/or to allow the roundabout to be placed at appropriate distances from existing structures. If roads have been added, removed or reconfigured in other ways near the roundabout, make these changes now.
 
 
The situation starts out like this, where the roads are no longer aligned with the new plan, and now there is a roundabout which we need to get created in Waze:
 
 
 
[[File:roundabout_01.png]]
 
 
 
  
This situation is fairly simple because all the segments are connected together already.
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[[File:RATracks.png|350x350px|left|alt=]]Oftentimes roundabouts are completed before aerial imagery is updated. In these cases, enable the GPS tracks layer in the map editor by pressing Shift+G, and use the tracks to guide your preparations. If the roads approaching the roundabout meet [[Best map editing practice#Divided and un-divided highways|the criteria for dividing roads]], make the roads divided where they will connect to the roundabout. Note that where road changes do not match aerial imagery, leaving a [[map comment]] is advised.
  
[[File:roundabout_02.png|320px|right]] The first thing to do is move the junction to the center of the roundabout. This is as simple as it sounds: click and drag the junction to where it should be.
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Once all preparations are made, hover the cursor over the Roads icon on the [[Map_Editor_Interface_and_Controls#The_Tool_Bar|toolbar]] and click '''Roundabout'''. You can also use the [[keyboard shortcut]] {{Key press|O}}.
{{Clear}}
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[[File:BuildRA.png|300x300px|right|alt=]] Move the cursor to the center of the actual roundabout. The cursor will be a crosshair '''+''' to indicate that it is in roundabout creation mode. Click once at the center and then move the mouse any direction towards the perimeter of the roundabout. An orange circle will grow and shrink as you move the mouse, with the numbers in the center of the circle displaying the radius of the resulting roundabout.
[[File:roundabout_03.png|320px|right]] Which gives us this:
 
{{Clear}}
 
[[File:roundabout_05.png|320px|right]] The two southern segments need to be disconnected from the center node and joined together below where the new road arches along the bottom of the screenshot. Once those are in place, draw the missing segment in between the roundabout location and the roads to the south of the roundabout.
 
{{Clear}}
 
 
 
If you look closely, you will see this roundabout actually does have four entry/exits, so let's also draw in the western road as just a small stub, for future use. This will also cause the roundabout to give the driver better instructions in terms of which exit to take, as a driver will see the stub exit in real life, and so will count that as an exit.
 
 
 
Once those are all created, go ahead and save the work.
 
 
 
 
 
[[File:Create Road Drop Down Menu.png|left]] ''Hover'' the cursor over the road with plus sign icon the right side of the [[Map_Editor_Interface_and_Controls#The_Tool_Bar|toolbar]] and ''click'' '''Roundabout'''. You can also use the [[keyboard shortcut]] which is the letter '''o''', selected because the shape of the letter is round, like a roundabout.
 
{{Clear}}
 
[[File:roundabout_06.png|320px|right]] Move the cursor to the center of the actual roundabout. The cursor will be a crosshair + to indicate it is in roundabout creation mode. Click once at the center and then move the mouse any direction towards the perimeter of the roundabout. An orangish circle will grow and shrink as you move the mouse, and the numbers in the center of the circle display the radius the roundabout will be.
 
 
 
[[File:roundabout_07.png|320px|right]] Click once when satisfied with the size and shape of the roundabout. What happens now is that the map editor creates new 1-way segments in between each road segment the circumference of the roundabout comes into contact with. Each of those segments is cut off and connected to the roundabout with allowed turns already set. All of these segments are shown in orange because they are not saved yet.
 
  
 +
[[File:ConfirmRA.png|300x300px|right|alt=]]Click once when satisfied with the size and shape of the roundabout, which will create new 1-way segments in between each road segment contacted by the edge of the orange circle. Each approaching segment is disconnected from the junction in the center and reconnected to the roundabout with allowed turns already set, but with some turns [[Soft and hard turns|unconfirmed]]. Make sure that each turn is confirmed.
 
{{Red|Any segments ''completely within'' the roundabout area will be deleted.}}
 
{{Red|Any segments ''completely within'' the roundabout area will be deleted.}}
{{Clear}}
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[[File:CompleteRA.png|300x300px|right|alt=]]Like all new roads, each roundabout segment needs the country, state and city filled in. Please see the [[Creating and editing road segments#Updating_details_to_confirm_the_road|updating details to confirm the road]] section for details on this process. If the roundabout doesn't have a name, which is usually the case, click the None box next to Street. If the roundabout is a named circle on local signs, its segments can be named just like any other road. This is particularly important if addresses are on the roundabout.To determine the road type, see [[User:Kartografer/Roundabout#Road type|the road type section below]]. To determine the speed limit, if applicable, see [[Speed limits#Roundabouts|the speed limits section on roundabouts]]. When the process is complete, all other attributes have been set, and the edits are saved, this is how the new roundabout looks:
[[File:roundabout_08.png|320px|right]] Just as with drawing new roads, the segments of the roundabout which were created in the last step must be confirmed in order for them to appear on the map in the Waze app. That is, each segment needs the country, state (where applicable), and city. Please see the [[Creating and editing road segments#Updating_details_to_confirm_the_road|Updating details to confirm the road]] section for details on this process. '''In Waze, we do NOT name roundabout segments. These segments remain unnamed using the "No Name" checkbox for street name to enable proper routing.''' If the roundabout is a named circle on local signs, then add a [[Places#Area|Place area type]] set as a ''Junction / Interchange'' filling the center area or covering the roundabout as appropriate using the name that appears on the local signs.
 
{{Clear}}
 
When the process is complete and the Save button has been clicked on one last time, this is how the new roundabout looks:
 
 
 
[[File:roundabout_09.png]]
 
 
 
 
 
For further reference, please [http://www.youtube.com/watch?v=hOPjWKjGCio watch this video on roundabout creation].
 
 
 
===Oval and very large shapes===
 
''If an oval or elliptical roundabout is required, hold down the '''Shift''' key.'' At this time only oval roundabouts along the North/South or East/West axis can be created. If an alternate shape or axis is desired, create a circular roundabout that is close to the correct shape and adjust the [[Creating and editing road segments#Adjusting_road_geometry_.28nodes.29|geometry nodes]] manually.
 
 
 
Note that roundabouts cannot be created over a maximum of {{:Roundabouts/Maximum}} in radius because of the danger of erasing all roads in the center could accidentally wipe out an entire city of roads. If a larger radius is required, use the same steps described above to alter the shape by adjusting the nodes as required.
 
{{Clear}}
 
 
 
==Improving manually drawn roundabouts==
 
[[Image:FixRAB-01.png|left|320px]]A well-meaning editor probably just didn't know how to create a new roundabout, so it was created by hand manually setting the segments as close to rounded as possible. The real problem is that Waze will not navigate these segments like a roundabout. This section of roadway will produce "turn right and then turn right" if being driven straight through. This is not what the driver will expect:
 
  
A proper roundabout, when being driven straight through, will tell drivers "at the roundabout, continue straight", "at the roundabout take the second exit" or some other numbered exit instruction depending on the size and number of nodes in the roundabout.
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Other considerations:
  
[[Image:FixRAB-02.png|320px|right]]The first step is to select and delete all the segments that make up the circle connecting the roads leading into the roundabout. That can be done individually or as a group.
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*If this roundabout is a local [[landmark]], such as Dupont Circle in Washington, DC, an [[Places|area place]] may also be drawn inside it with the Park and/or Junction/Interchange categories, as appropriate.
{{Clear}}
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*If signage for any roundabout exit does not match what would be generated by the primary name of the exiting segment, add a customized [[turn instruction]] at the exit.
 +
*Some new roundabouts may be announced by local authorities before their construction, complete with road closures. If this is the case, map the roundabout in this way while following the procedures outlined for [[scheduled reconfigurations]].
 +
*For further reference, please [http://www.youtube.com/watch?v=hOPjWKjGCio watch this video on roundabout creation].
  
[[Image:FixRAB-03.png|320px|left]]Next, extend the segments deeper into the center of the roundabout area. They need to end inside the final perimeter of the roundabout, otherwise they will not be linked automatically during the final step of creating the roundabout. During this step be sure to center the roadway segments from the middle of their respective roads. Unless the actual road has a significant divider between the incoming and outgoing lanes on a road, avoid creating two separate one-way roads leading into and out of the roundabout ''([[#Entrances and exits|See Below]]).'' Press Save to ensure there are no errors before going to the next step.
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===Oval, large or unusual shapes===
{{Clear}}
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[[File:PeanutRA.png|thumb|This roundabout is shaped like a peanut; it was created with the roundabout tool and then manually squished into this shape. It has closures ending on its opening date and a map comment.]]If an oval or elliptical roundabout is required, hold down the '''Shift''' key during roundabout creation''.'' At this time only oval roundabouts along the north/south or east/west axis can be created. If an alternate shape or axis is desired, create a circular roundabout that is close to the correct shape and adjust the [[Creating and editing road segments#Adjusting_road_geometry_.28nodes.29|geometry handles]] manually.
  
[[Image:FixRAB-04.png|320px|right]]Now select Roundabout from the pencil icon, or hit O on the keyboard. The cursor turns into a small cross. Click and hold the left mouse button at the center of the roundabout area and extend outward until you reach the proper diameter. When the diameter is correct, release the mouse button to create the new roundabout.
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Note that roundabouts cannot be created over a maximum of {{:Roundabouts/Maximum}} in radius because of the danger that erasing all roads in the center could accidentally wipe out an entire city of roads. If a larger radius is required, create the roundabout at the maximum size allowed by the creation tool, then manually [[User:Kartografer/Roundabout#Adjusting geometry|adjust its geometry]] to make it bigger.
  
If the aerial imagery does not show a new roundabout that exists today, use the GPS tracking layer to estimate where the center of the roundabout is located.
 
 
{{Clear}}
 
{{Clear}}
  
[[Image:FixRAB-06.png|320px|left]]After saving the roundabout will be red. This indicates that the roundabout road segments have not been confirmed. To do that select the roundabout segments and ensure the country and state are selected. Also set the city or mark it as no city. Roundabout segments usually have no name, so check the None box next to the street field. Named roundabout segments do not cause problems with routing or navigation instructions, however, and may be necessary for [[House Numbers in WME|house numbers]] if houses lie directly on the named roundabout. An area place can also be drawn for the named roundabout under the category '''Junction / Interchange'''.
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==Creation from nothing==
{{Clear}}
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[[Image:FixRAB-03.png|200x200px|alt=|right]]Draw all of the road segments that will lead to the roundabout and ensure they extend into the center of the roundabout area. Use the visual map to align the roads. From there, create the roundabout just as described in the section above.
  
After [[Creating and editing road segments#Updating_details_to_confirm_the_road|confirming the individual roundabout road segments]], there is now a properly-formed roundabout which will give the correct routing instructions:
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At least one segment must intersect the roundabout when it is being created; otherwise, nothing will happen. To avoid problems with [[loops]], it is best to make the roundabout intersect segments in at least three places.
 
 
[[Image:FixRAB-07.png]]
 
 
 
Note that roundabouts should never be created with just one segment. Roundabouts should be intersected by two or more road segments. Review the [[Junction Style Guide]] for information on creating a [[Junction_Style_Guide#No_Outlet_Roads|loop]] or a [[Junction_Style_Guide#No_Outlet_Roads|dead end]].
 
 
 
==Creating a roundabout from nothing==
 
Draw all of the road segments that will lead to the roundabout and ensure they extend into the center of the roundabout area. Use the visual map to align the roads. From there, create the roundabout just as is described in the two sections above.
 
 
 
Note that there must be at least one road segment partially inside the area of the roundabout being created, otherwise no roundabout will be created.
 
 
 
==Adjusting geometry==
 
When a segment of a roundabout is selected, the geometry points (white circles) will appear. Each of these circles can be moved by dragging them with the mouse to align better with the visual map or the GPS traces.
 
 
 
When initially creating a roundabout, it is possible to create an oval or elliptical shape by holding the '''Shift''' key when stretching the diameter before it is created. Only oval roundabouts along the North/South or East/West axis can be created. If an alternate shape is desired, adjust the geometry points as described above.
 
  
 
==Road type==
 
==Road type==
 
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It is common to have multiple [[road types]] meeting at a roundabout. For proper routing and consistent appearance, the correct road type must be assigned to the roundabout itself. The road types of interest in are, in order from highest to lowest, {{Freeway}}, {{Major Highway}}, {{Minor Highway}}, {{Primary Street}}, {{Street}}, {{Parking Lot Road}}, and {{Private Road}}. Since a roundabout is not a [[Junction Style Guide/Interchange|limited-access interchange]], two freeways should never meet at a roundabout; however, it is conceivable that a freeway might begin or end at one.
It is possible to have multiple types of roads ({{Street}}, {{Primary Street}}, {{Minor Highway}}, etc.) meeting at a roundabout.
 
 
 
To minimize inefficient routing, it is important to be careful with the road type assigned to the Roundabout itself. Any [[routing penalty]] going from connected roads to the roundabout must be kept to a minimum, but it should not be too "attractive" where routing through it is encouraged when unnecessary.
 
 
 
The [[road types]] of interest in are, in order from highest to lowest, {{Freeway}}, {{Major Highway}}, {{Minor Highway}}, {{Primary Street}}, {{Street}}, {{Parking Lot Road}}, and {{Private Road}}. Since a Roundabout is '''not''' a [[Limited Access Interchange Style Guide|Limited Access Interchange]], two Freeways should never meet at a roundabout; however, it is conceivable that a Freeway might begin or end at one.
 
  
 
To determine what road type to use for the Roundabout:
 
To determine what road type to use for the Roundabout:
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|-
 
|-
 
|}
 
|}
{{Clear}}
 
 
 
==Understanding navigation instructions==
 
==Understanding navigation instructions==
 
Waze supports two different styles of roundabout navigation instructions. One style instructs simply to turn or continue at the roundabout, while the other instructs how many exits one must pass before leaving the roundabout. The US editing community terms these two instruction styles as "normal" and "non-normal" respectively. The term "normal" is used here in its mathematical sense to mean "orthogonal", "perpendicular", or "at right angles".
 
Waze supports two different styles of roundabout navigation instructions. One style instructs simply to turn or continue at the roundabout, while the other instructs how many exits one must pass before leaving the roundabout. The US editing community terms these two instruction styles as "normal" and "non-normal" respectively. The term "normal" is used here in its mathematical sense to mean "orthogonal", "perpendicular", or "at right angles".
  
This section will explain the difference between a normal and a non-normal roundabout.
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This section will explain the difference between normal and non-normal roundabout instructions.
 
<br />
 
<br />
Normal roundabouts:  
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Normal roundabout instructions:  
  
*Require '''all''' of the following
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*Require '''all''' of these conditions:
 
**2-4 nodes.
 
**2-4 nodes.
 
**All exit nodes aligned within "normal" range of the entry node
 
**All exit nodes aligned within "normal" range of the entry node
**A diameter less than 50 meters
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**A radius less than 25 meters
*Provide the following instructions:
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*Comprise the following:
**"[[Interactive junction instruction algorithm#At the roundabout turn right|At the roundabout turn right]]"
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**"[[Interactive junction instruction algorithm#At the roundabout turn right|At the roundabout, turn right]]"
**"[[Interactive junction instruction algorithm#At the roundabout continue straight|At the roundabout continue straight]]"
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**"[[Interactive junction instruction algorithm#At the roundabout continue straight|At the roundabout, continue straight]]"
**"[[Interactive junction instruction algorithm#At the roundabout turn left|At the roundabout turn left]]"
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**"[[Interactive junction instruction algorithm#At the roundabout turn left|At the roundabout, turn left]]"
**"[[Interactive junction instruction algorithm#At the roundabout make a U-turn|At the roundabout make a U-turn]]"
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**"[[Interactive junction instruction algorithm#At the roundabout make a U-turn|At the roundabout, make a U-turn]]"
  
Non-normal roundabouts:
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Non-normal roundabout instructions:
  
*Require '''at least one''' of the following:
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*Require '''at least one''' of these conditions:
 
**'''5''' or more nodes.
 
**'''5''' or more nodes.
 
**Nodes outside the normal roundabout angle range
 
**Nodes outside the normal roundabout angle range
**A diameter greater than 50 meters.
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**A radius greater than 25 meters.
*Provide the following instructions:
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*Comprise the following:
**"[[Interactive junction instruction algorithm#At the roundabout take the .23xx exit|At the roundabout take the ''n''th exit]]"
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**"[[Interactive junction instruction algorithm#At the roundabout take the .23xx exit|At the roundabout, take the ''n''th exit]]"
  
 
''A roundabout can be both normal and non-normal at the same time depending on your entry node, because the roundabout angle is calculated from where one enters the roundabout.''<br />
 
''A roundabout can be both normal and non-normal at the same time depending on your entry node, because the roundabout angle is calculated from where one enters the roundabout.''<br />
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The '''''roundabout angle''''' is the angle of any segment connected to the roundabout from the perspective of ''the origin''. This is basically the same as the [[wikipedia:Central_angle|central angle]] of a circle. The actual ''turn angle'' of the segments is irrelevant.<br>To explain;
 
The '''''roundabout angle''''' is the angle of any segment connected to the roundabout from the perspective of ''the origin''. This is basically the same as the [[wikipedia:Central_angle|central angle]] of a circle. The actual ''turn angle'' of the segments is irrelevant.<br>To explain;
  
*Draw an imaginary line through the center of the roundabout to the other side of the roundabout from junction node where ''the origin'' joins the roundabout. This will represent a 0° '''''roundabout angle''''', any deviation to the right or left will increase the angle.
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*Draw an imaginary line through the center of the roundabout to the other side of the roundabout from the junction node where ''the origin'' joins the roundabout. This will represent a 0° '''''roundabout angle''''', any deviation to the right or left will increase the angle.
 
*Draw another imaginary line across the roundabout through the center and perpendicular to the first imaginary line. This will represent a 90° '''''roundabout angle''''' to either side.
 
*Draw another imaginary line across the roundabout through the center and perpendicular to the first imaginary line. This will represent a 90° '''''roundabout angle''''' to either side.
  
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====Segment angles====
 
====Segment angles====
 +
[[File:RABent1.png|frameless|left]]
 +
[[File:RAStraight1.png|frameless|right]]
 +
Since the angles of the segments approaching the nodes do not matter, both of these layouts will give the same instructions. Only the angles between the nodes and the center of the roundabout (roundabout angles) determine which instructions are given.{{Clear}}
 +
<br />
  
*Since the angles of the segments approaching the nodes do not matter, both of these layouts will give the same instructions. Only the angles between the nodes and the center of the roundabout (roundabout angles) determine which instructions are given.<br />
 
 
[[Image:RABent.png|240px]][[Image:RAStraight.png|240px]]
 
<br />
 
<br />
 
 
====Three incoming segments====
 
====Three incoming segments====
 +
[[File:RANormal1.png|thumb|Both exit nodes have roundabout angles within the normal range of ±15° from 0° or 90°.|alt=]]Let's assume this roundabout has a radius of less than 25 meters, so the other criteria are met for normal instructions.
 +
'''Coming from node 1, this is how we see the roundabout:'''
  
*'''Let's assume this roundabout has a radius of less than 25 meters, so the other criteria are met for normal instructions.'''
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:*With respect to node 1, nodes 2 and 3 have roundabout angles within the normal range (90&deg;&plusmn;15&#176; & 0&deg;&plusmn;15&deg;).
*'''Coming from node #1, this is how we see the roundabout:'''
+
:*Exiting at node 2 produces [[File:Nav icon roundabout right 1.jpg|50x50px]] "at the roundabout, turn right".
 
+
:*Exiting at node 3 produces [[File:Nav icon roundabout straight.JPG|50x50px]] "at the roundabout, continue straight".
[[File:RANormal.png|thumb|right|360px|Both exit nodes have roundabout angles within the normal range of ±15° from 0° or 90°.]]
 
<br />
 
 
 
:*Both exits 2 and 3 have roundabout angles within the normal range (90&deg;&plusmn;15&#176; & 0&deg;&plusmn;15&deg;).
 
 
 
<br />
 
 
 
:*''These exits will get an instruction to "turn right" or "continue straight".''
 
 
 
<br clear="all" />
 
 
 
*'''Coming from node #3, this is how we see the roundabout:'''
 
  
[[File:RANNormal.png|thumb|right|360px|Node 2 has a roundabout angle that is outside the normal range of ±15° from 90°]]
+
[[File:RANNormal1.png|thumb|Node 2 has a roundabout angle that is outside the normal range of ±15° from 90°|alt=]]
<br />
+
'''Coming from node 3, this is how we see the roundabout:'''
  
:*Exit 1 is within the normal roundabout angle range, but exit 2 is not within the normal roundabout angle range. <br />
+
:*With respect to node 3, node 1 is within the normal roundabout angle range, but node 2 is not.
:*''Even though one of these exits is within normal range, the roundabout itself is ‘non-normal’ and both exits will get the "take the X exit" prompt. The entire roundabout must be normal to generate "turn left", "turn right" or "continue straight" instructions.''
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:*Exiting at node 1 produces [[File:Nav icon roundabout 1.JPG|50x50px]] "at the roundabout, take the first exit".
 +
:*Exiting at node 2 produces [[File:Nav icon roundabout 2.JPG|50x50px]] "at the roundabout, take the second exit".
  
<br clear="all" />
+
'''All exits must be within the normal range with respect to a given entrance in order to generate "turn left", "turn right", "continue straight" or "make a U-turn" instructions from this entrance.'''
  
 
==Entries and exits==
 
==Entries and exits==
[[Image:RdAbt-NoDivRd.png|150px|right]]
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[[Image:RdAbt-NoDivRd.png|150px|right]][[Image:RdAbt-DivRd.png|150px|right]]
The road segments leading into and out of a roundabout are generally drawn as simple two-way roads connected perpendicular (90 degrees) to the roundabout circle itself. This makes it easier on the user to visualize the map into reality by not having the incoming lanes appear separately on the map and only see the exits.
+
If the road segments approaching a roundabout do not meet the [[Best map editing practice#Divided and un-divided highways|criteria for dividing roads]], they are generally drawn as simple two-way roads connected perpendicular (90 degrees) to the roundabout circle itself. If they do meet the criteria for dividing, each entry or exit segment should be connected to its own node on the roundabout, and the segments should be drawn in a way that fits with the natural flow of traffic. This will almost always cause the roundabout instructions to be non-normal. Due to historical reasons, some regions of the USA have a preponderance of normal or non-normal roundabouts, and the users in those regions are accustomed to one or the other set of instructions. Check with your regional leadership to determine which instructions are preferred when drawing roundabouts.
 
 
In some large or irregular roundabouts the incoming and exit roadways may be so far away from each other that it would be better to have them split into two separate one-way segments. Each entry or exit segment should be connected to its own node on the roundabout. This will almost always cause the roundabout instructions to be non-normal. Due to historical reasons, some regions of the USA have a preponderance of normal or non-normal roundabouts, and the users in those regions are accustomed to one or the other set of instructions. Check with your regional leadership to determine which instructions are preferred when drawing roundabouts.
 
  
 
===Multiple segments at one node===
 
===Multiple segments at one node===
In general, it's only appropriate to connect multiple segments to a single node of a roundabout if the exit leaves the roundabout to the left of the entry, such as, for example, both directions of a divided highway meeting at one node. This will be treated exactly like a single two-way segment in navigation instructions.
+
It is usually inappropriate to join two segments at the same node on a roundabout and tends to cause problems. If both segments are one way in opposing directions, and the exit is to the left of the entrance, such as with both roadways of a divided highway, these will be treated correctly like a single two-way segment in navigation instructions. However, this geometry results in sharp turns that rarely fit the natural flow of traffic turning into and out of the roundabout, and it is often better simply to join each one-way segment at its own node on a roundabout.
  
 
Do not connect an entry belonging to one road to or past an exit belonging to the next road to the right, as this causes the first exit not to be counted and the subsequent exits to be numbered incorrectly. Even if the movement into and out of the roundabout is prohibited at this point (often the case in [[#At-grade connector|roundabouts with bypasses]]), if it is physically possible, users will tend to count it as the first exit, and we need to provide a consistent experience when mapping.
 
Do not connect an entry belonging to one road to or past an exit belonging to the next road to the right, as this causes the first exit not to be counted and the subsequent exits to be numbered incorrectly. Even if the movement into and out of the roundabout is prohibited at this point (often the case in [[#At-grade connector|roundabouts with bypasses]]), if it is physically possible, users will tend to count it as the first exit, and we need to provide a consistent experience when mapping.
  
Do not connect more than one exit (either two-way segments or outgoing one-way segments) to the same node at a roundabout, as this causes Waze not to number any exit. In these cases Waze will show an empty circle for the roundabout instruction and will simply truncate the spoken instruction to "at the roundabout."
+
Do not connect more than one exit (either two-way segments or outgoing one-way segments) to the same node at a roundabout, as this causes Waze not to number any exit. In these cases Waze will show an empty circle for the roundabout instruction and will truncate the spoken instruction to "at the roundabout."
==Moving junctions and disconnecting roads==
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==Adjusting geometry==
When adjusting roundabouts, drag the junction nodes and move/delete the geometry points of the segments. Do not disconnect or reconnect roads just to adjust angles. Apart from the loss of turn data that happens with disconnections, some nodes can't be deleted from roundabouts, and changing segment IDs within them (caused by cutting and merging) can cause them not to work properly.{{ReturnTo | Editing manual | the editing manual}}
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When adjusting roundabouts, drag the junction nodes and move/delete the geometry points of the segments. This is better than disconnecting and reconnecting, because disconnection results in the loss of turn data. The script [[Scripts/WME RA Util|WME RA Util]] makes adjustment of roundabouts much easier.
 
==Bypass==
 
==Bypass==
 
Some roundabouts are designed with physically separated '''bypass roads''' or '''[[at-grade connectors]] (AGCs)'''. In many cases, roundabout bypasses can be mapped just like any other, but some roundabouts with bypasses have persistent routing problems.
 
Some roundabouts are designed with physically separated '''bypass roads''' or '''[[at-grade connectors]] (AGCs)'''. In many cases, roundabout bypasses can be mapped just like any other, but some roundabouts with bypasses have persistent routing problems.
  
 
===Correcting inappropriate avoidance of roundabout bypasses===
 
===Correcting inappropriate avoidance of roundabout bypasses===
[[File:RA-bad.png|thumb|The example on the left had entrances of one road connected to exits of a different road at the same nodes, and it gave incorrect normal instructions. The example on the right had entrances of one road connected past exits of the next road, and it gave incorrectly numbered non-normal instructions.]]<!--
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Where bypasses have been built to allow right-turning or straight traffic to avoid the roundabout altogether, Waze might send traffic through the roundabout anyway.  This is often confusing to drivers when it is contrary to regulatory or informative signs. In these cases, use a [[junction box]] to restrict the invalid route through the roundabout, which will force the bypass to be routed.
-->Where bypasses have been built to allow right-turning or straight traffic to avoid the roundabout altogether, Waze might send traffic through the roundabout anyway,  if Waze thinks the roundabout is even a few seconds faster at a certain time of day. If there are any difficulties with assigning traffic to the correct segments at this junction, Waze may be incorrect.  This is often confusing to drivers when it is contrary to regulatory or informative signs.
 
  
Junction boxes cannot be applied to control turns in roundabouts, so other approaches have been explored.
 
 
====What not to do====
 
====What not to do====
Do not junction the incoming and outgoing segment at the same node in order to prevent the redundant turn. [[#Multiple segments at one node|Multiple segments at one node]] causes incorrect exit numbering, and, in some cases the distortion can cause incorrect ''normal'' instructions, (for example -  "at the roundabout, turn right" to users continuing straight, if they travel through only 90° of the roundabout from entry to exit).
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[[File:RA-bad.png|thumb|Entrances of one road connected to exits of a different road at the same nodes give incorrect normal instructions (left). Entrances of one road connected past exits of the next road give incorrectly numbered non-normal instructions (right).]][[File:RAhacks.png|thumb|Hacks to activate the [[Routing penalties/Controlling U-turn penalties|U-turn penalty]] (left) and the [[Detour Prevention Mechanisms|detour prevention penalty]] (right) should no longer be used.]]Before junction boxes were developed to work with roundabouts, various hacks were used to force bypass routing. Some involved connecting the entrance of one road at or past the exit of the next road, in order to prevent the redundant turn through the roundabout and force routing through the bypass. Others involved the activation of penalties on the redundant turn to force routing through the bypass. None of these should be used.
 
 
Do not move the incoming segment after the outgoing segment to make Waze avoid the exit.  This is also a distortion if the roundabout and can cause incorrect roundabout instructions,
 
 
 
{{Mbox|type=warning|text=Because the following solutions are hacks, do not use them unless improper avoidance of the bypass has been persistently demonstrated in real route testing; work under the supervision of local leadership.}}
 
 
 
====Fake U-turn prevention====
 
[[File:RA-UTP.png|thumb|The movement from SR-101, through the selected roundabout segment and out to SR-10 is penalized, because the junction angles add up to 180° and the roundabout segment is short and straight.]]One solution is to activate the [[Routing penalties/Controlling U-turn penalties|three-segment U-turn penalty]]. The Waze routing engine treats the entry to, exit from and short connecting segment of the roundabout are treated the same as though they were the opposing directions and connecting median segment of a divided road.  If the conditions are met, the 3-segment turn will almost always be prevented. To use:
 
 
 
#Make sure that path to be avoided uses 3 segments (in, roundabout, and out).
 
#Move the nodes so that the roundabout segment is {{:Routing penalties/U-turn minimum|less}} long or less.
 
#On the entry and exit segments, move geometry points very close to the nodes so that at the roundabout segment, the entry and exit segment are within five degrees of parallel.
 
#*Do not depend upon the sum of angles between the 3 segments unless the roundabout segment is completely straight. You may create a temporary straight segment to check the angles, then undo the change.
 
  
If all three criteria are satisfied (three segments in the movement, roundabout segment length and parallelism), a large penalty will be applied to the movement into and out of the U-turn, making this route extremely unlikely in most situations.
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*Do not junction the incoming and outgoing segment at the same node in order to prevent the redundant turn. [[#Multiple segments at one node|Joining multiple entrances or exits at one node]] causes incorrect exit numbering, and, in some cases the distortion can cause incorrect ''normal'' instructions, (for example -  "at the roundabout, turn right" to users continuing straight, if they travel through only 90° of the roundabout from entry to exit).
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*Do not move the incoming segment after the outgoing segment to make Waze avoid the exit.  This is also a distortion if the roundabout and can cause incorrect roundabout instructions.
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*Do not activate fake U-turn and detour penalties by means of unconventional road names and types or unnatural geometry.
  
Because a short roundabout segment is required, this hack generally will not be useful when normal roundabout instructions are desired, or in other cases where the entrance and exit are not very close.
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Wherever found, these deviations '''should be removed and replaced''' with junction boxes as described in the next section.
  
====Fake or real detour prevention====
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==Junction box==
[[File:RA-BDP.png|thumb|US-41 S is the continuous name coming from the west, bypassing the roundabout and continuing south on all {{Major Highway|MH}} segments. The segment from the roundabout going south is unnamed and has the {{Minor Highway|mH+1}} type, so the movement from US-41 S, into the roundabout and back out to US-41 S is penalized as a detour.]]Another solution is to activate the [[Detour Prevention Mechanisms#Big detours|big detour penalty]]. This treats the movement into and out at the next exit as a detour away from the bypass. To use:
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[[File:JuBRA.png|thumb|A junction box has been used to force right turning traffic on US-41 S to use the bypass rather than being routed through the roundabout. Normal turn instructions have also been specified in accordance with regional norms, lane markings and signage]]Junction boxes can be used over roundabouts, covering them either partially or fully. In addition to providing better timing, using a junction box on a roundabout can accomplish these goals:
  
#Make sure that the segment before the bypass, the bypass and the segment after the bypass all share a name.
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#As mentioned above, they may be used to correct routing problems.
#*If no real named or numbered road continues through the bypass, a fake alt name can be used, such as "BDP" or "roundabout hack."
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#They may be used to provide customized [[Turn instruction|turn instructions]] where signage for a particular exit is different when coming from different entrances.
#*A [[turn instruction override]] will probably be necessary to force a turn instruction into the bypass.
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#They may also be used to override the default navigation instructions.
#Make sure that these three segments all share the same road type group.
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#*For example, divided roads may meet at a small roundabout, where drivers would expect normal instructions based on signs, lane markings and what's common in the region. Rather than using unnatural geometry to force the normal instructions, draw a junction box to encircle the roundabout and set the [[voice prompt]] for each path through the roundabout to Turn left, Turn right, U-turn or Continue.
#Along the path to be avoided, select the entrance segment that leads from the roundabout to the end of the bypass (the last segment of the detour), remove all names (they will be [[Navigation instructions for unnamed segments|inherited]] in instructions from other entrances) and change the road type to be of a different group from the bypass and its bracketing segments.
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#*Conversely, where non-normal instructions are desired that would otherwise be normal, make a junction box voice prompt of Let Waze count the exit number.
##To ensure proper pruning behavior, the [[Road types#Routing road type|routing road type]] of this segment may be adjusted to match those it connects.
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#*Where [https://safety.fhwa.dot.gov/saferjourney1/library/countermeasures/27.htm small traffic-calming circles] have been mapped as roundabouts, a junction box may be used to suppress unnecessary "at the roundabout, continue straight" instructions. Check with local leadership on how to handle traffic-calming circles.
  
If all detour criteria are met, a significant penalty will be applied to the movement away from the bypass, through the roundabout and back, causing the bypass to be preferred in routing.
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If the junction box completely contains only nodes on the roundabout, its voice prompts will produce the proper roundabout spoken and visual instructions, such as "at the roundabout, turn right" and "at the roundabout, take the fourth exit". Normal and non-normal instructions can be used in the same roundabout. If nodes '''outside the roundabout''' are included in the junction box, the navigation instructions '''will not work as expected''', so be sure to only include roundabout segments when using a junction box to control roundabout instructions.
  
This solution makes sense when the roundabout path is truly a detour from the highway (the segment or segments bypassing the roundabout carry a numbered highway).  It cannot be used if the roads connected by the bypass are not highways, or if one is a minor highway and the other is a major highway or freeway road type.
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{{ReturnTo | Editing manual | the editing manual}}

Latest revision as of 01:26, 31 October 2021

Roundabouts, rotaries, or traffic circles, are unique segments of roadway in the Waze routing system. When a driver approaches a roundabout, a specific icon is displayed in the turn direction area of the display with a number corresponding to the exit count from the driver's entry into the roundabout or with a symbol of the movement through the roundabout. Manually creating a circular road will not produce these instructions.

What is a roundabout and what is not

In general when there is a clear roundabout in imagery, it is best to have it mapped as a roundabout in the road layer. There are a few cases that should not be mapped as roundabouts.

These are not drawn as roundabouts
Description Image
Streets intersect, but there is no center island preventing left turns. There are no signs indicating a roundabout approaching the intersection or painted on the ground. RdAbt-Not1.png
A single road segment leading to a cul-de-sac should be drawn as a dead end. With very large roads it might be advisable to create a three-segment loop but not a roundabout. Jct cul-de-sac island ex.png
Small traffic-calming circles are usually not drawn as roundabouts, especially if they do not increase the size of the intersection greater than that of a simple four-way intersection, have no roundabout signs or yield signs and have stop signs on at least one approach. Check with local leadership on how to map traffic circles. TrafficCircleSquare.png

Creation from an intersection

First, move the junction to the center of the roundabout. Click and drag the junction to where it should be. We also need to adjust the incoming segments so that they align with the roads leading into the roundabout. When roundabouts are built at existing intersections, the approaching segments are usually realigned for drivers to reach optimal speeds when entering and exiting the roundabout and/or to allow the roundabout to be placed at appropriate distances from existing structures. If roads have been added, removed or reconfigured in other ways near the roundabout, make these changes now.

Oftentimes roundabouts are completed before aerial imagery is updated. In these cases, enable the GPS tracks layer in the map editor by pressing Shift+G, and use the tracks to guide your preparations. If the roads approaching the roundabout meet the criteria for dividing roads, make the roads divided where they will connect to the roundabout. Note that where road changes do not match aerial imagery, leaving a map comment is advised.

Once all preparations are made, hover the cursor over the Roads icon on the toolbar and click Roundabout. You can also use the keyboard shortcut O.

Move the cursor to the center of the actual roundabout. The cursor will be a crosshair + to indicate that it is in roundabout creation mode. Click once at the center and then move the mouse any direction towards the perimeter of the roundabout. An orange circle will grow and shrink as you move the mouse, with the numbers in the center of the circle displaying the radius of the resulting roundabout.

Click once when satisfied with the size and shape of the roundabout, which will create new 1-way segments in between each road segment contacted by the edge of the orange circle. Each approaching segment is disconnected from the junction in the center and reconnected to the roundabout with allowed turns already set, but with some turns unconfirmed. Make sure that each turn is confirmed.

Any segments completely within the roundabout area will be deleted.

Like all new roads, each roundabout segment needs the country, state and city filled in. Please see the updating details to confirm the road section for details on this process. If the roundabout doesn't have a name, which is usually the case, click the None box next to Street. If the roundabout is a named circle on local signs, its segments can be named just like any other road. This is particularly important if addresses are on the roundabout.To determine the road type, see the road type section below. To determine the speed limit, if applicable, see the speed limits section on roundabouts. When the process is complete, all other attributes have been set, and the edits are saved, this is how the new roundabout looks:

Other considerations:

  • If this roundabout is a local landmark, such as Dupont Circle in Washington, DC, an area place may also be drawn inside it with the Park and/or Junction/Interchange categories, as appropriate.
  • If signage for any roundabout exit does not match what would be generated by the primary name of the exiting segment, add a customized turn instruction at the exit.
  • Some new roundabouts may be announced by local authorities before their construction, complete with road closures. If this is the case, map the roundabout in this way while following the procedures outlined for scheduled reconfigurations.
  • For further reference, please watch this video on roundabout creation.

Oval, large or unusual shapes

This roundabout is shaped like a peanut; it was created with the roundabout tool and then manually squished into this shape. It has closures ending on its opening date and a map comment.

If an oval or elliptical roundabout is required, hold down the Shift key during roundabout creation. At this time only oval roundabouts along the north/south or east/west axis can be created. If an alternate shape or axis is desired, create a circular roundabout that is close to the correct shape and adjust the geometry handles manually.

Note that roundabouts cannot be created over a maximum of 100 m (328 feet) in radius because of the danger that erasing all roads in the center could accidentally wipe out an entire city of roads. If a larger radius is required, create the roundabout at the maximum size allowed by the creation tool, then manually adjust its geometry to make it bigger.

Creation from nothing

Draw all of the road segments that will lead to the roundabout and ensure they extend into the center of the roundabout area. Use the visual map to align the roads. From there, create the roundabout just as described in the section above.

At least one segment must intersect the roundabout when it is being created; otherwise, nothing will happen. To avoid problems with loops, it is best to make the roundabout intersect segments in at least three places.

Road type

It is common to have multiple road types meeting at a roundabout. For proper routing and consistent appearance, the correct road type must be assigned to the roundabout itself. The road types of interest in are, in order from highest to lowest,  Freeway ,  Major Highway ,  Minor Highway ,  Primary Street ,  Street ,  Parking Lot Road , and  Private Road . Since a roundabout is not a limited-access interchange, two freeways should never meet at a roundabout; however, it is conceivable that a freeway might begin or end at one.

To determine what road type to use for the Roundabout:

  1. Identify the two connected segments with the highest type listed above:
    • If a particular road goes through a roundabout, count the road as two separate segments, one on each side of the roundabout.
    • If a road on one side of the roundabout is a divided roadway made of two one-way road segments, count the pair of one-way segments as a single segment.
    • The two connected segments with the highest type may have the same type or different types.
    • If a ramp connects to the Roundabout, use the road type to which that ramp connects.
  2. Select the roundabout and set the road type as follows.
    • If the two highest-type segments have the same type, use that type.
    • If the two highest-type segments have different types, use the lower type of those two segments.
Roundabout Road Type Guide
Description Top 2 Road Types
RA Type
Example
A Primary Street and a Street cross at a Roundabout so we have two Street segments connected and two Primary Street segments connected.  Primary Street 

 Primary Street 

RdAbt PrPr.png
One Primary Street segment and three Street segments meet.  Primary Street 

 Street 

RdAbt PrSt.png
Three Primary Street segments and one Street segment meet.  Primary Street 

 Primary Street 

RdAbt PrPr3.png
A Major Highway and a Minor Highway cross so we have two segments of each type.  Major Highway 

 Major Highway 

RdAbt MjMj.png
Three Major Highway segments and one Minor Highway segment meet.  Major Highway 

 Major Highway 

RdAbt MjMj3.png
A Major Highway, two Primary Streets, and one Street segment meet. (The Major Highway can be thought to start/end at the Roundabout.)  Major Highway 

 Primary Street 

RdAbt MjPr.png
A Major Highway, a Primary Street, and two Street segments meet at a Roundabout.  Major Highway 

 Primary Street 

RdAbt MjPr2.png
A Major Highway, a Minor Highway, and two Primary Street segments meet. (If we used Primary Street, routing would be penalized going from the Minor Highway to the Major Highway.)  Major Highway 

 Minor Highway 

RdAbt MjMn.png
Same as above, except the Major Highway and Minor Highway are divided roadways. (Recall that a divided roadway is treated as one "segment" for this rule.)  Major Highway 

 Minor Highway 

Roundabout - split roads.png
A Ramp (connected to a Major Highway), a Minor Highway, and two Primary Street segments meet. (Recall that the type connected to the ramp is used in the analysis. Effectively, it's the same as the previous two examples.)  Major Highway 

 Minor Highway 

Roundabout - ramp.png
Only Ramp segments are connected to a Roundabout. If every segment connected is a Ramp, so is the Roundabout. (When only Ramps connect to a Roundabout, none of the connected road types are considered.)  Ramp  Roundabout - all ramps.png

Understanding navigation instructions

Waze supports two different styles of roundabout navigation instructions. One style instructs simply to turn or continue at the roundabout, while the other instructs how many exits one must pass before leaving the roundabout. The US editing community terms these two instruction styles as "normal" and "non-normal" respectively. The term "normal" is used here in its mathematical sense to mean "orthogonal", "perpendicular", or "at right angles".

This section will explain the difference between normal and non-normal roundabout instructions.
Normal roundabout instructions:

Non-normal roundabout instructions:

  • Require at least one of these conditions:
    • 5 or more nodes.
    • Nodes outside the normal roundabout angle range
    • A radius greater than 25 meters.
  • Comprise the following:

A roundabout can be both normal and non-normal at the same time depending on your entry node, because the roundabout angle is calculated from where one enters the roundabout.

Roundabout angle

The roundabout angle is the angle of any segment connected to the roundabout from the perspective of the origin. This is basically the same as the central angle of a circle. The actual turn angle of the segments is irrelevant.
To explain;

  • Draw an imaginary line through the center of the roundabout to the other side of the roundabout from the junction node where the origin joins the roundabout. This will represent a 0° roundabout angle, any deviation to the right or left will increase the angle.
  • Draw another imaginary line across the roundabout through the center and perpendicular to the first imaginary line. This will represent a 90° roundabout angle to either side.
Roundabouts
Normal Non-normal
Roundabout 3 normal.png

Roundabout 3 non-normal.png

All other segments are within the allowed ±15° from either 0° or 90°. Not all other segments are within the allowed ±15° from either 0° or 90°.

Examples

Segment angles

RABent1.png
RAStraight1.png

Since the angles of the segments approaching the nodes do not matter, both of these layouts will give the same instructions. Only the angles between the nodes and the center of the roundabout (roundabout angles) determine which instructions are given.


Three incoming segments

Both exit nodes have roundabout angles within the normal range of ±15° from 0° or 90°.

Let's assume this roundabout has a radius of less than 25 meters, so the other criteria are met for normal instructions.

Coming from node 1, this is how we see the roundabout:

  • With respect to node 1, nodes 2 and 3 have roundabout angles within the normal range (90°±15° & 0°±15°).
  • Exiting at node 2 produces Nav icon roundabout right 1.jpg "at the roundabout, turn right".
  • Exiting at node 3 produces Nav icon roundabout straight.JPG "at the roundabout, continue straight".
Node 2 has a roundabout angle that is outside the normal range of ±15° from 90°

Coming from node 3, this is how we see the roundabout:

  • With respect to node 3, node 1 is within the normal roundabout angle range, but node 2 is not.
  • Exiting at node 1 produces Nav icon roundabout 1.JPG "at the roundabout, take the first exit".
  • Exiting at node 2 produces Nav icon roundabout 2.JPG "at the roundabout, take the second exit".

All exits must be within the normal range with respect to a given entrance in order to generate "turn left", "turn right", "continue straight" or "make a U-turn" instructions from this entrance.

Entries and exits

RdAbt-NoDivRd.png
RdAbt-DivRd.png

If the road segments approaching a roundabout do not meet the criteria for dividing roads, they are generally drawn as simple two-way roads connected perpendicular (90 degrees) to the roundabout circle itself. If they do meet the criteria for dividing, each entry or exit segment should be connected to its own node on the roundabout, and the segments should be drawn in a way that fits with the natural flow of traffic. This will almost always cause the roundabout instructions to be non-normal. Due to historical reasons, some regions of the USA have a preponderance of normal or non-normal roundabouts, and the users in those regions are accustomed to one or the other set of instructions. Check with your regional leadership to determine which instructions are preferred when drawing roundabouts.

Multiple segments at one node

It is usually inappropriate to join two segments at the same node on a roundabout and tends to cause problems. If both segments are one way in opposing directions, and the exit is to the left of the entrance, such as with both roadways of a divided highway, these will be treated correctly like a single two-way segment in navigation instructions. However, this geometry results in sharp turns that rarely fit the natural flow of traffic turning into and out of the roundabout, and it is often better simply to join each one-way segment at its own node on a roundabout.

Do not connect an entry belonging to one road to or past an exit belonging to the next road to the right, as this causes the first exit not to be counted and the subsequent exits to be numbered incorrectly. Even if the movement into and out of the roundabout is prohibited at this point (often the case in roundabouts with bypasses), if it is physically possible, users will tend to count it as the first exit, and we need to provide a consistent experience when mapping.

Do not connect more than one exit (either two-way segments or outgoing one-way segments) to the same node at a roundabout, as this causes Waze not to number any exit. In these cases Waze will show an empty circle for the roundabout instruction and will truncate the spoken instruction to "at the roundabout."

Adjusting geometry

When adjusting roundabouts, drag the junction nodes and move/delete the geometry points of the segments. This is better than disconnecting and reconnecting, because disconnection results in the loss of turn data. The script WME RA Util makes adjustment of roundabouts much easier.

Bypass

Some roundabouts are designed with physically separated bypass roads or at-grade connectors (AGCs). In many cases, roundabout bypasses can be mapped just like any other, but some roundabouts with bypasses have persistent routing problems.

Correcting inappropriate avoidance of roundabout bypasses

Where bypasses have been built to allow right-turning or straight traffic to avoid the roundabout altogether, Waze might send traffic through the roundabout anyway. This is often confusing to drivers when it is contrary to regulatory or informative signs. In these cases, use a junction box to restrict the invalid route through the roundabout, which will force the bypass to be routed.

What not to do

Entrances of one road connected to exits of a different road at the same nodes give incorrect normal instructions (left). Entrances of one road connected past exits of the next road give incorrectly numbered non-normal instructions (right).
Hacks to activate the U-turn penalty (left) and the detour prevention penalty (right) should no longer be used.

Before junction boxes were developed to work with roundabouts, various hacks were used to force bypass routing. Some involved connecting the entrance of one road at or past the exit of the next road, in order to prevent the redundant turn through the roundabout and force routing through the bypass. Others involved the activation of penalties on the redundant turn to force routing through the bypass. None of these should be used.

  • Do not junction the incoming and outgoing segment at the same node in order to prevent the redundant turn. Joining multiple entrances or exits at one node causes incorrect exit numbering, and, in some cases the distortion can cause incorrect normal instructions, (for example - "at the roundabout, turn right" to users continuing straight, if they travel through only 90° of the roundabout from entry to exit).
  • Do not move the incoming segment after the outgoing segment to make Waze avoid the exit. This is also a distortion if the roundabout and can cause incorrect roundabout instructions.
  • Do not activate fake U-turn and detour penalties by means of unconventional road names and types or unnatural geometry.

Wherever found, these deviations should be removed and replaced with junction boxes as described in the next section.

Junction box

A junction box has been used to force right turning traffic on US-41 S to use the bypass rather than being routed through the roundabout. Normal turn instructions have also been specified in accordance with regional norms, lane markings and signage

Junction boxes can be used over roundabouts, covering them either partially or fully. In addition to providing better timing, using a junction box on a roundabout can accomplish these goals:

  1. As mentioned above, they may be used to correct routing problems.
  2. They may be used to provide customized turn instructions where signage for a particular exit is different when coming from different entrances.
  3. They may also be used to override the default navigation instructions.
    • For example, divided roads may meet at a small roundabout, where drivers would expect normal instructions based on signs, lane markings and what's common in the region. Rather than using unnatural geometry to force the normal instructions, draw a junction box to encircle the roundabout and set the voice prompt for each path through the roundabout to Turn left, Turn right, U-turn or Continue.
    • Conversely, where non-normal instructions are desired that would otherwise be normal, make a junction box voice prompt of Let Waze count the exit number.
    • Where small traffic-calming circles have been mapped as roundabouts, a junction box may be used to suppress unnecessary "at the roundabout, continue straight" instructions. Check with local leadership on how to handle traffic-calming circles.

If the junction box completely contains only nodes on the roundabout, its voice prompts will produce the proper roundabout spoken and visual instructions, such as "at the roundabout, turn right" and "at the roundabout, take the fourth exit". Normal and non-normal instructions can be used in the same roundabout. If nodes outside the roundabout are included in the junction box, the navigation instructions will not work as expected, so be sure to only include roundabout segments when using a junction box to control roundabout instructions.