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Junction Style Guide

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The following article contains key information on properly creating junctions and the roadways between them. Be sure to review it in its entirety before editing the map.
 
== Simple is better ==
When representing junctions (a.k.a. , intersections, interchanges, cross roads, corners, etc.) between roads, we sometimes have the Waze map does not need to blur the lines between perfectly match the physical and logical worldsroad layouts it represents. The primary goal should be is to represent things the real world as simply as possible in the maps and only introduce complexity in the maps to deal address complex issues. == The basics ==This guide requires a complete understanding of editing the maps with an issue[[Waze Map Editor]] (WME)=== Map editing 101 ===Although it is highly recommended to read the [[editing manual]] before touching the map, it is required that you do not continue with this guide until you have read the following:* [[Map Editing Quick-start Guide|Map Editing Quick-start Guide]]* [[Creating and editing road segments#Junctions|Moving and removing junctions]]
== The Basics =Junction definition ==={| class="Wikitable floatright"| [[Image:Junction_selected.png|50px|border]]| [[Image:Uneditable_junction.png|50px|border]]| [[Image:junction_unsaved.png|50px|border]]|}The [[Glossary#Junction or Junction Point|Glossary on Junctions]] provides details on how junctions can appear differently in the editor depending on its state or condition.
Lets start with the very basic case A junction is made up of one three things:# Two or more road [[Creating and editing road branching off from another. Most of segments|segments]]# One point where all the time they will probably segments meet at close to a 90 degree angle(the [[junction point]] itself)# [[Map Editing Quick-start Guide#Turn restrictions .28allowed turns. This is the simplest situation 29|Turns allowed or restricted]] when traveling from one segment to deal with since the physical and logical views of the roads match up very well.another through that junction point{{clear}}
== Controlling Turn Instructions =={| class="Wikitable floatright" cellpadding="5" border="1" style="text-align: [[Imagecenter; border:Jct_3_901px solid darkgray;"|-| Keep Right || Keep Left|-| Turn Right || Turn Left|-| Exit Right || Exit Left|}Turn instructions are critical for proper client navigation. They are controlled by:* The angle set between segments at junctions.* The road names.* The road types.png]]
But you will probably find roads that meet at odd angles as well. Even in urban areas with rigid grids, you will often find at least one road that has existed since prior to Review the establishment article [[Junction Style Guide/Controlling turn instructions|controlling turn instructions]] for a complete understanding of the grid which cuts through town at strange angles. The initial urge will be to represent the junction as it is in the physical world - two lines running into each other at some anglerequirements and issues surrounding this topic.
: [[Image:Jct_3_45.png]]== Surface Streets ==
But there are issues with this method. Depending on the angles, the client may give a === Intersections ==={| class="Keep RightWikitable floatright" instruction to the driver when a | [[File:Jct 3 90.png|x100px|border]]| [[File:Jct 4 90.png|x100px|border]]| [[File:Jct ramp no geo.png|x100px|border]]|-| colspan="Turn Right3" instruction is more appropriate|[[File:4waysplitsplit. In some cases, it is even possible the angle may be such that no instruction is given png|border|center|169x169px]]|}Basic intersections involve three or four road segments meeting at alla single point. Or worse yet, the routing engine may determine that it isn't possible to make a very sharp angle and not suggest a turn (in the example image, headed south and then turning left to head east)Some more complex variations resemble H or # shapes.
To eliminate ambiguity, we need to treat the junction from a logical point of view. Since we want to be given basic "Turn Left" and "Turn Right" instructions, we have In all cases it is important to treat it like it was a basic 90 degree intersectionconfigure these intersections properly. But how do we do that when the roads don't actually diverge at 90 degrees? What we need to do Detailed information is to add some geometry nodes to make the branch road leave the main road at close to 90 degrees, then we gradually curve to match covered in the true departure angle[[Junction Style Guide/Intersections|Intersections]] article.{{clear}}
: [[Image:Jct_3_45_curve.png]]
Now we have a junction that logically works like a basic 90 degree junction but it also fits the reality of the physical world.=== No Outlet Roads ===
A ramp Roads which only have one way in and one way out can present challenges to a highway is another good example where additional geometry nodes are helpful. Especially since most ramps diverge at a very small angle from the roadrouting server, although they seem simple to our minds.
: [[Image:Jct_ramp_no_geo.png]]==== Dead Ends ====
The drawback in this case Dead Ends (which also exists for a.k.a. No Exit, Closed, No Through Road, No Outlet) are road segments that simply end, with no continuation or connections at one end. In some areas, a Dead End may be synonymous with a [[#Cul-de-sacs|Cul-de-sac]]. In the side US, a "No Outlet" sign may be used to indicate a road example above!) which itself is that not a dead end, but it may only connects to other dead end roads. It can also be very hard used as a "friendlier" alternative to see and click on the turn restriction arrows in the editortypical Dead End sign.
: [[Image:Jct_ramp_no_geo_arrowWithin the Map Editor it is possible to represent a dead end road with multiple segments if there are private driveways or parking lot roads mapped and connected. In that case, only the very last segment is considered the dead end segment.png]]
But if we [[File:Jct dead end.png|left|border]]Make sure that there is a junction indicator (the small blue dot, not just add one more a geometry node to make ) at the departure angle at very end of the segment. While this one segment does not actually constitute a junction itself closer , the small blue dot is a visual indicator to 45 degreesthe editor that the end of this segment is properly set up.This is necessary to ensure proper routing out of the segment.See the Cul-de-sac section below on when and how to fix this.
: [[ImageFile:Jct_ramp_w_geoJct dead end ex.png|right|border|200px]]This final junction indicator must be located near the end of the road, but it should be located where there is still pavement as not to negatively impact client routes. Waze only considers the road fully traversed if both ends of the segment are fully crossed. If the junction indicator at the end of the segment happens to be at the edge of the pavement (or off of the road surface if aerials are not exactly aligned), it will be very difficult for a driver to cross that junction. A good rule of thumb is to have the end of the segment the same distance from the end of the pavement as it is from each side of the road.
With such a placement, the driver is given a chance to cross that junction indicator for that segment...now Also check for the proper u-turn setting as covered in the [[Map Editing Quick-start Guide#U-Turns at the arrows are visible and accessibleend of dead-end-streets|best practices article on u-turns]].
: [[Image:Jct_ramp_w_geo_arrow.png]]==== Cul-de-sacs ====
We can easily scale the above approaches to a four way junction''See also: [http://en. Again we can expect to mostly see angles close to 90 degreeswikipedia.org/wiki/Cul-de-sac Cul-de-sac article on Wikipedia]''
: [[Image:Jct_4_90A Cul-de-sac (a.k.a. Court in the US) is a common treatment of a dead end street in a residential neighborhood.png‎ ]]
And if we have that odd In almost every situation, a cul-de-sac should be treated exactly as a dead end street cutting across town at an odd angle, we again want to avoid with the final junction indicator in the center of the bulb of the cul-de-sac. Be sure the odd angle free end of the final road segment has small blue dot displayed at the junction.tip (when not editing or selecting the segment).If there is no blue dot, please correct it by following the steps for [[Creating and editing road segments#Fix the end-node on cul-de-sacs and dead-ends|fixing dead ends]].
: [[Image:Jct_4_45Jct_cul-de-sac_ex.png|left|border]]The junction indicator should be located close to the middle of the bulb and NOT near the outer edges. If the end of the segment is positioned along the perimeter of the bulb, there may be difficulty in processing client routes. Waze only considers the road fully traversed if both ends of a segment are crossed. If the end of the segment happens to be on the curb (or off of the road surface if aerials are not exactly aligned), it will be very difficult for a driver to cross the end of the road segment. With the junction in the middle of the visual road, we give a driver a good chance to cross the end of the segment no matter where they drive within the bulb. The exception to this guidance is given in the next example.{{clear}}
{| class="Wikitable floatright"| [[Image:Jct_cul-de-sac_island_ex.png|200px|border]]| [[Image:Jct_cul-de-sac_island_ex_road.png|border|200px]]|}This cul-de-sac, with a small island, should be treated as a basic dead end with no loop.and we want to use geometry nodes to bring the actual junction to 90 degrees. You The island can zoom in as close be ignored, as you can and add a single geometry node on each side. This will give us there is no significant routing question for the proper angle but make it virtually invisible driver once they get to users so it looks just like the physical worldcul-de-sac.
: [[Image:Jct_4_45_curveAs for placement of the final junction indicator, here we may get better results by moving the junction out from the true center and over to the outer perimeter of the central island.png]]The shift ensures that the driver has a good opportunity to cross the end of the segment.{{clear}}
The above image is what you would see zoomed However, if the cul-de-sac has a very large bulb with a large island in the middle, it may better be treated as close as possiblea [[#Loops|Loop]]. Zoomed back outA good rule of thumb is if you were standing at the end of the cul-de-sac, can you tell that it looks is just a cul-de-sac? Or does it look like two different roads? If you see an island, but are not sure if it is significant, leave the image showing Loop out. If "Missing Road" errors occur on the junction without any geometry nodesroad, then add a Loop.
== Controlling Turn Instructions =Loops ===<gallery mode="packed-hover">File:U-shaped Road.jpg|U-shaped roadFile:Jct loop bulb.png|terminal or dead-end loop</gallery>Road segments form a loop when you can trace a path from a starting point around to the same point without retracing any portion of the traced path. ==== Every loop must be made up of three or more segments ====[[File:Loop_3-part_6.jpg|right|150px]]Any loop that does not follow this rule can cause problems for the Waze routing server. If there is no side-street, you must [[Map Editing Quick-start Guide#Splitting a segment|insert an extra junction node]] along the loop. Many new editors will see the extra junction node(s), assume they are not needed, and delete them. Please educate new editors. ====Two-segment loops====Two-segment loops create a situation called "same endpoint drivable segments" or "same connection segments". There are two or more ways to get from one junction node to another without going through any other nodes. They can cause a problem for the Waze app regardless of the direction, or other attributes of the segments. This is because the routing server gives your mobile app a list of node IDs only, but the app needs to tell you which segments to drive on. If there are two ways to get from one node to the next without going through any other nodes, then the Waze app might just have to guess. It might guess a detour off the highway through a service road or scenic overlook. Please save Waze from this silliness. Correct two-segment loops.
In ====One-segment loops===={{anchor|Loop_save_errors}}[[File:Dead end loop.png|thumb|right]] One-segment or self-connected loops are often found in basemap areas. It is difficult for Waze editors to create one-segment loops. Depending on the Basics section abovesituation, we touched these should be converted to three-segment loops or simple dead-end roads. For more on loops on how dead-end roads, please see [[Cul-de-sac#Cul-de-sacs|cul-de-sac]]. It is important to ensure preserve house number data on these segments.===== Fixing one-segment loops=====If you try to edit a "Turn left/right" instruction would be given over a "Keep left/right" instruction.one-segment loop, but then cannot save the changes, undo your changes and then try one of the following to fix it:
Details *If the loop and the road leading to it have the '''same''' name*#Select the loop and the road.*#Click the bridge icon that appears (one end of the mechanics behind this can be found on loop will disconnect from the other)*#Move the [[How_Waze_determines_turn_now free end of the loop so it is slightly separated*#Save*If the loop and the road leading to it have '''different''' names*#Draw a new road segment that connects to the loop/_keep_/_exit_maneuvers|How Waze determines turn / keep / exit maneuvers]] page, but here road junction*#Give that new road the same exact name as the loop*#Select the loop and the new road segment*#Click the bridge icon that appears (one end of the loop will disconnect from the other)*#Move the now free end of the loop so it is slightly separated*#Save*Create a quick summarydead end road or a three-segment dead-end loop as appropriate.=== Geometry ===*Fix elevations.*Confirm turns.
Some of the complexity of the back-end algorithms can be avoided if we try to treat junctions with the logical view in mind as was done in the previous examplesHere is a [http://www.youtube. If all junctions you edit follow just a few basic forms, it will be much easier to predict com/watch?v=a7yAzG7HElw video on YouTube showing the behavior of an individual junctionsecond method].{{#widget:YouTube|id=a7yAzG7HElw}}
* Approximately '''90''' degree departure angle = '''Turn'''* Less than '''45''' degree departure angle = '''Keep''' (or Exit for Ramps)[[Image:Jct_roundabout.png|frameless|right]]
This knowledge allows us ===Roundabouts and traffic circles===It may be tempting to control how use the roundabout feature to create a junction behaves by modifying loop shape. Do not do this unless the loop is a single geometry node in most casesroundabout or traffic circle. This is often useful Roundabouts give special routing instructions, and must not be used for other purposes. To learn more, please see the [[At-Grade_Connectors|At-Grade ConnectorsRoundabout]] where sometimes we prefer a "Keep right/left" and other times a "Turn right/left" would be more appropriatepage.
If we keep the departure angle less than 45 degrees, we would get a "Keep Right" to follow the curved one=== At-way connector:grade connectors ===
: [[Image:Jct_at_grade_keep.png]]
But if we move one geometry node With exceptions, don't set these segments as ramps! Watch out for all of the turns you need to create restrict. For a 90 degree anglemore detailed discussion, now we would receive see the full [[At-grade connectors]] article. == Interchanges and ramps == An '''interchange''' is a road junction where two roads are connected by dedicated roadways, called '''ramps'''. The roads connected by an interchange do not intersect one another directly, and if they cross, the crossing is grade-separated. === When to use ramps === Use of the {{Ramp}} type is governed by the following rules:* [[Road types]]* [[At-grade connectors]] === Ramp and interchange style === For guidance on the proper configuration of ramps, interchanges and wayfinders, see [[Junction Style Guide/Interchange]]. == Special Cases ===== Transitions ==={| class="Turn RightWikitable floatright" instruction| [[Image:Jct_transition.png|x150px|border]]| [[Image:Jct_transition_90.png|x150px|border]]|}A transition is a non-junction depicted using a junction node.
Valid examples of where to use a Transition node include: # Road name changes# City Limits# Road Direction changes# Part of a [[Image:Jct_at_grade_turn.png#Loops|Loop Road]]# Speed Limit Change
=== Segment Naming and Type ===Before the current house numbering system came into use, transition nodes were used to aid in house numbering, but that is no longer required.
Besides the geometry of There may be existing transition nodes on the map for other reasons like remaining after a connecting road segmentsis deleted, inherited from the names original base map import when rivers and types of the segments come into playstreams created junctions, etc.
As long as you are '''certain''' it is not a valid transition node, a superfluous junction node may be [[Map Editing Quick-start Guide#Delete a Junction|deleted]]. Doing so will simplify the map, eliminate turn restrictions to maintain, and reduce computing resource needs. Also consider removing the [[Creating and editing road segments#Adjusting road geometry .28nodes.29|geometry node]] which will replace the junction node you delete, if that geometry node is not needed. === Roads to Nowhere ===In certain situations it may be necessary to add road segments that are un-drivable in order to provide accurate navigation instructions. ==== Actual ====A basic rule valid use of this technique is at the temporary end of thumb a freeway. As a freeway is built, it is often opened in sections, up to a certain exit. If we map this as a regular freeway segment leading to a ramp segment, no announcement will be made for that final exit, no matter what we name the exit ramp. This can be confusing if the ramp is set up as a properly signed and numbered exit, especially if a driver is traveling a long distance on this freeway. Imagine traveling down a freeway and seeing your next instruction is "turn left at Main St." You would probably wonder if there was a map error since you want shouldn't be making a left turn to be announcedoff of a freeway. If we map even just a little of the future path of the freeway, having this gives the routing engine a different name junction which will improve generate an "exit" instruction at the end of the chances that will happenfreeway, thus eliminating any confusion. For the At-Grade Connector example above Conversely, if we do NOT want an exit instruction at the connector should have end of a different name than the freeway, ensure there are no road it is leaving (See segments extending past the [[At-Grade_Connectors#How_to_name_the_connector|How final exit, to name ensure the final exit is the connector]] section only path out of the At-Grade Connectors page)final freeway segment.
== Oddities ==
=== Offset Roads ===
[[Image:Jct_4_offset.png|left|x150px|border]]Sometimes you will find two roads which cross , where one does not quite line up exactly from one side to with the other.
There are a few things we need to look at in this situation.{{clear}}: * Do the roads actually line up in reality? If so we need to modify the junction to be a basic 4-way junction.{| class="Wikitable floatright"|[[Image:Jct_4_offsetJct_4_offset_align.png|x150px|border]]|[[Image:Jct_4_offset_align_ex.png|x150px|border]]|}:* Do the roads ALMOST line up in reality? If you were giving instructions to a person and would tell them to go straight with no mention of any slight turn or jog, then we want to make it into a 4-way junction. You may need to "split the difference" and not follow the centerline of either road to achieve this. The angles are exaggerated in this next example to show how the junction is forced to be close to 90 degrees, then we taper to the true centerlines of the roads. In practice this can be much more gradual and/or done while zoomed in very close.[[Image:Jct_4_offset_ex.png|right|x150px|border]]:* Finally, is there a true separation between the roads? Would you need to say for example "turn left then make an immediate right"? If so then we will want to leave the junction such that the two sides do not align.{{clear}}
There are [[Image:Jct_4_offset_sep_ex.png|left|x150px|border]]Since we want to avoid very short segments of road (the GPS chips in consumer devices can be very inaccurate which may make it seem that a few things we need driver skipped right over a short segment. This will result in [[Map Problems in Waze Map Editor|automated map errors]] and possible route recalculations in the client,) it may be wise to look at shift the side roads as far apart from each other as possible with them still in this situationthe proper location (along the far curb lines for a residential street for example). This will maximize the length of the short segment between the side roads.
# Do the roads actually line up in reality? If so we need to modify the junction to be a basic 4 way junction.[[Category:Style Guide]]# Do the roads ALMOST line up in reality? If you were giving instructions to a person and would tell them to go straight with no mention of any slight turn or jog, then we want to make it into a 4 way junction. You may need to "split the difference" and not follow the centerline of either road to achieve this. The angles are exaggerated in this next example to show how the junction is forced to be close to 90 degrees, then we taper to the true centerlines of the roads. In practice this can be much more gradual and/or only done while zoomed in very close.<br/>[[ImageCategory:Jct_4_offset_align.pngTable examples]]<br/># Finally, is there a true separation between the roads? Would you need to say for example "turn left then make an immediate right"? If so then we will want to leave the junction such that the two sides do not align. Since we want to avoid very short segments of road, it may be wise to shift the side roads as far apart from each other as possible with them still in the proper location (along the far curb lines for a residential street for example). This will maximize the length of the short segment between the side roads.