Difference between revisions of "Roundabouts"
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| − | * A Street and a Primary Street | + | * A Street and a Primary Street cross at a Roundabout so we have two Street segments connected and two Primary Street segments connected. The Roundabout should be type Primary Street (top 2 = both Primary Street). |
| − | * Three | + | * Three Street segments and one Primary Street segment meet. The Roundabout should be type Street (top 2 = Street and Primary Street). |
| − | * One Street and three Primary | + | * One Street segment and three Primary Street segments meet. The Roundabout should be type Primary Street (top 2 = both Primary Street) |
| − | * A Minor Highway and a Major Highway | + | * A Minor Highway and a Major Highway cross so we have two segments of each type. The Roundabout should be type Major Highway (top 2 = both Major Highway). |
| − | * One minor Highway and three Major | + | * One minor Highway segment and three Major Highway segments meet. The Roundabout should be type Major Highway (top 2 = Major Highway). |
| − | * A Major Highway, two Primary Streets, and one Street meet. The Roundabout should be type Primary Street (top 2 = Major Highway and Primary Street). The Major Highway can be thought to start/end at the Roundabout. | + | * A Major Highway, two Primary Streets, and one Street segment meet. The Roundabout should be type Primary Street (top 2 = Major Highway and Primary Street). The Major Highway can be thought to start/end at the Roundabout. |
| − | * A Major Highway, a Minor Highway, and two Primary | + | * A Major Highway, a Minor Highway, and two Primary Street segments meet. The Roundabout should be type Minor Highway (top 2 = Major Highway and Minor Highway). If we used Primary Street, routing would be penalized going from the Minor Highway to the Major Highway. |
| − | * Two Streets, a Primary Street and a Major Highway meet at a Roundabout (top 2 = Major Highway and Primary Street). The Roundabout should be type Primary Street. | + | * Two Streets, a Primary Street and a Major Highway segment meet at a Roundabout (top 2 = Major Highway and Primary Street). The Roundabout should be type Primary Street. |
==Adjusting geometry== | ==Adjusting geometry== | ||
Revision as of 16:13, 23 August 2012
Roundabouts, rotaries, or traffic circles, are unique segments of roadway in the Waze router. 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. Manually creating a circular road will not tell Waze to navigate the area as a roundabout.
Creating a roundabout from an intersection
Often times, when streets become more congested, planners will install a traffic circle, or roundabout, to get traffic to flow more freely. This section shows you the steps to get from an existing intersection to a new roundabout.
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:
This situation is fairly simple because all the segments are connected together already.
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.
Which gives us this:
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.
If you look closely, you will see this roundabout actually does have four entrance/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.
Hover the cursor over the large + icon at the right side of the 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.
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 diameter the roundabout will be.
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 nodes manually.
Click once when you are 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.
WARNING: Any segments completely within the roundabout area WILL BE DELETED.
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 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. If the roundabout is a named circle, then a landmark filling the center area may be added to show the name.
When the process is complete and the Save button has been clicked on one last time, this is how the new roundabout looks:
For further reference, please watch this video on roundabout creation.
Creating a roundabout from nothing
Create one or more roads leading into the center of the roundabout area. Use the visual map to align the roads leading into the roundabout. From there create the roundabout just as is described above for converting an intersection to a roundabout.
Note that there must be at least one road leading inside the area of the roundabout being created, otherwise no roundabout will be created when you use that option.
Editing existing roundabouts
It looks like a roundabout, but isn't
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 you went straight through. This is not what the driver will expect:
A proper roundabout will tell you to "enter the roundabout and take the first exit" when going straight through, so we need to fix this "fake" roundabout.
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.
Next, extend the segments deeper into the center of the roundabout area. They need to end inside the final diameter 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. Avoid creating two separate one-way roads leading into and out of the roundabout as this creates some visual confusion unless the actual road has a significant divider between the incoming and outgoing lanes on that one road. It is better to use single two-way roads when connecting to the roundabout. Press Save to ensure there are no errors before going to the next step.
Now select Roundabout from the + menu, 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.
If the visual map layer does not show a new roundabout that exists today, use the GPS tracking layer to estimate where the center of the roundabout is located.
After saving you will notice the roundabout is red. This indicates you have not yet confirmed the roundabout road segments. 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. For the road name, leave that blank as no road name to allow the routing server to operate properly. If the roundabout is named it will not route as expected. Alternately you can create a landmark at the center of the roundabout and name it as desired.
After confirming the individual roundabout road segments, there is now a properly-formed roundabout which will give the correct routing instructions:
Note that you cannot create a roundabout with only one segment. You must have the roundabout be intersected by two or more roads. After reviewing the Junction Style Guide for the alternative of a loop or just dead-end and you still believe it should be a full roundabout, just create the roundabout with two segments. When complete the second segment can be deleted leaving the roundabout portion split into two segments.
If when creating your roundabout you do not cross any roads, the roundabout cannot be created. There must be at least one road connected.
Road Type
It is possible to have multiple types of roads (Streets, Primary Streets, Minor Highway, etc.) meeting at a roundabout.
To minimize inefficient routing, we need to be careful with what type we assign to the Roundabout itself. We want to minimize any penalty going from connected roads, but we also do not want to make the Roundabout too "attractive" where we encourage routing through it when unnecessary.
Since a Roundabout is not a Limited Access Interchange, we ignore any Freeway segments in this discussion. The road types we are interested in are, in order from highest to lowest, Major Highway, Minor Highway, Primary Street, Street. We will consider Service Road, Private Road, and Parking Lot Road the same as Street for now.
To determine what road type to use for the Roundabout:
- Identify the two connected segments with the HIGHEST type (the two can have the same type)
- Pick the LOWEST type of those two segments.
Examples:
- A Street and a Primary Street cross at a Roundabout so we have two Street segments connected and two Primary Street segments connected. The Roundabout should be type Primary Street (top 2 = both Primary Street).
- Three Street segments and one Primary Street segment meet. The Roundabout should be type Street (top 2 = Street and Primary Street).
- One Street segment and three Primary Street segments meet. The Roundabout should be type Primary Street (top 2 = both Primary Street)
- A Minor Highway and a Major Highway cross so we have two segments of each type. The Roundabout should be type Major Highway (top 2 = both Major Highway).
- One minor Highway segment and three Major Highway segments meet. The Roundabout should be type Major Highway (top 2 = Major Highway).
- A Major Highway, two Primary Streets, and one Street segment meet. The Roundabout should be type Primary Street (top 2 = Major Highway and Primary Street). The Major Highway can be thought to start/end at the Roundabout.
- A Major Highway, a Minor Highway, and two Primary Street segments meet. The Roundabout should be type Minor Highway (top 2 = Major Highway and Minor Highway). If we used Primary Street, routing would be penalized going from the Minor Highway to the Major Highway.
- Two Streets, a Primary Street and a Major Highway segment meet at a Roundabout (top 2 = Major Highway and Primary Street). The Roundabout should be type Primary Street.