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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 between , intersections, interchanges, cross roads, we sometimes have corners, etc., 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 address complex issues. == The basics ==This guide requires a complete understanding of editing the maps with [[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]] === 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. A junction is made up of three things:# Two or more road [[Creating and editing road segments|segments]]# One point where all the segments meet (the [[junction point]] itself)# [[Map Editing Quick-start Guide#Turn restrictions .28allowed turns.29|Turns allowed or restricted]] when traveling from one segment to another through that junction point{{clear}} == Controlling Turn Instructions =={| class="Wikitable floatright" cellpadding="5" border="1" style="text-align:center; border: 1px 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. Review the article [[Junction Style Guide/Controlling turn instructions|controlling turn instructions]] for a complete understanding of the requirements and issues surrounding this topic. == Surface Streets == === Intersections ==={| class="Wikitable floatright"| [[File:Jct 3 90.png|x100px|border]]| [[File:Jct 4 90.png|x100px|border]]| [[File:Jct ramp no geo.png|x100px|border]]|-| colspan="3"|[[File:4waysplitsplit.png|border|center|169x169px]]|}Basic intersections involve three or four road segments meeting at a single point. Some more complex variations resemble H or # shapes. In all cases it is important to configure these intersections properly. Detailed information is covered in the [[Junction Style Guide/Intersections|Intersections]] article.{{clear}}  === No Outlet Roads === Roads which only have one way in and one way out can present challenges to the routing server, although they seem simple to our minds. ==== Dead Ends ==== Dead Ends (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 US, a "No Outlet" sign may be used to indicate a road which itself is not a dead end, but it only connects to other dead end roads. It can also be used as a "friendlier" alternative to the typical Dead End sign. Within 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. [[File:Jct dead end.png|left|border]]Make sure that there is a junction indicator (the small blue dot, not just a geometry node) at the very end of the segment. While this one segment does not actually constitute a junction, the small blue dot is a visual indicator to the 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 deal fix this. [[File:Jct 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. Also check for the proper u-turn setting as covered in the [[Map Editing Quick-start Guide#U-Turns at the end of dead-end-streets|best practices article on u-turns]]. ==== Cul-de-sacs ==== ''See also: [ Cul-de-sac article on Wikipedia]'' A Cul-de-sac (a.k.a. Court in the US) is a common treatment of a dead end street in a residential neighborhood. In almost every situation, a cul-de-sac should be treated exactly as a dead end street, with the final junction indicator in the center of the bulb of the cul-de-sac. Be sure the free end of the final road segment has small blue dot displayed at the 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_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. The island can be ignored, as there is no significant routing question for the driver once they get to the cul-de-sac. As 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. The shift ensures that the driver has a good opportunity to cross the end of the segment.{{clear}} However, if the cul-de-sac has a very large bulb with a large island in the middle, it may better be treated as a [[#Loops|Loop]]. A good rule of thumb is if you were standing at the end of the cul-de-sac, can you tell that it 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 Loop out. If "Missing Road" errors occur on the road, then add a Loop. === 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 issueextra 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. ====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 situation, these should be converted to three-segment loops or simple dead-end roads. For more on loops on dead-end roads, please see [[Cul-de-sac#Cul-de-sacs|cul-de-sac]]. It is important to preserve house number data on these segments.===== Fixing one-segment loops=====If you try to edit a one-segment loop, but then cannot save the changes, undo your changes and then try one of the following to fix it: *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 loop will disconnect from the other)*#Move the 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/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 dead end road or a three-segment dead-end loop as appropriate.*Fix elevations.*Confirm turns. Here is a [ video on YouTube showing the second method].{{#widget:YouTube|id=a7yAzG7HElw}} [[Image:Jct_roundabout.png|frameless|right]] ===Roundabouts and traffic circles===It may be tempting to use the roundabout feature to create a loop shape. Do not do this unless the loop is a roundabout or traffic circle. Roundabouts give special routing instructions, and must not be used for other purposes. To learn more, please see the [[Roundabout]] page. === At-grade connectors === : [[Image:Jct_at_grade_keep.png]] With exceptions, don't set these segments as ramps! Watch out for all of the turns you need to restrict. For a more detailed discussion, 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 ===
== The Basics ==For guidance on the proper configuration of ramps, interchanges and wayfinders, see [[Junction Style Guide/Interchange]].
Lets start with the very basic case of one road branching off from another== Special Cases ===== Transitions ==={| class="Wikitable floatright"| [[Image:Jct_transition. Most of the time they will probably meet at close to a 90 degree anglepng|x150px|border]]| [[Image:Jct_transition_90. This png|x150px|border]]|}A transition is the simplest situation to deal with since the physical and logical versions of the roads match up very wella 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_3_90.png#Loops|Loop Road]]# Speed Limit Change
But you will probably find roads that meet at odd angles as well. Even Before the current house numbering system came into use, transition nodes were used to aid in urban areas with rigid gridshouse numbering, you will often find at least one road but that has existed since prior to the establishment 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 angleno longer required.
[[Image:Jct_3_45There may be existing transition nodes on the map for other reasons like remaining after a connecting road is deleted, inherited from the original base map import when rivers and streams created junctions, etc.png]]
But there As long as you are issues with this method'''certain''' it is not a valid transition node, a superfluous junction node may be [[Map Editing Quick-start Guide#Delete a Junction|deleted]]. Depending on Doing so will simplify the anglesmap, the client may give a "Keep Right" instruction eliminate turn restrictions to maintain, and reduce computing resource needs. Also consider removing the driver when a "Turn Right" instruction is more appropriate[[Creating and editing road segments#Adjusting road geometry .28nodes. In some cases29|geometry node]] which will replace the junction node you delete, it is even possible the angle may be such if that no instruction geometry node is given at all. 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)needed.
To eliminate ambiguity, we need to treat the junction from a logical point of view. Since we want === Roads to Nowhere ===In certain situations it may be given basic "Turn Left" and "Turn Right" instructions, we have to treat it like it was a basic 90 degree intersection. But how do we do that when the roads don't actually diverge at 90 degrees? What we need to do is necessary to add some geometry nodes to make the branch road leave the main road at close segments that are un-drivable in order to 90 degrees, then we gradually curve to match the true departure angleprovide accurate navigation instructions.
[[Image:Jct_3_45_curve==== Actual ====A valid use of this technique is at the temporary end of 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.png]]
Now we have 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 junction that logically works like map error since you shouldn't be making a basic 90 degree junction but it also fits the reality left turn off of the physical worlda freeway.
We can easily scale If we map even just a little of the future path of the above approaches to freeway, this gives the routing engine a four way junction. Again we can expect to mostly see angles close to 90 degreeswhich will generate an "exit" instruction at the end of the freeway, thus eliminating any confusion.
[[Image:Jct_4_90Conversely, if we do NOT want an exit instruction at the end of a freeway, ensure there are no road segments extending past the final exit, to ensure the final exit is the only path out of the final freeway segment.png‎ ]]
And if we have that odd street cutting across town at an odd angle=== Offset Roads ===[[Image:Jct_4_offset.png|left|x150px|border]]Sometimes you will find two roads which cross, we again want to avoid the odd angle at where one does not quite line up with the junction..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_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_45Jct_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}}
[[Image:Jct_4_offset_sep_ex...and png|left|x150px|border]]Since we want to use geometry nodes to bring avoid very short segments of road (the actual junction to 90 degreesGPS chips in consumer devices can be very inaccurate which may make it seem that a driver skipped right over a short segment. You can zoom 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 shift the side roads as close far apart from each other as you can and add possible with them still in the proper location (along the far curb lines for a single geometry node on each sideresidential street for example). This will give us maximize the proper angle but make it virtually invisible to users so it looks just like length of the short segment between the physical worldside roads.
[[ImageCategory:Jct_4_45_curve.pngStyle Guide]][[Category:Table examples]]