Best map editing practice View history

Revision as of 00:34, 22 December 2010 by Harling (talk | contribs) (Filled in some content)

Like Waze, this page is a community effort and a work in progress. Many helpful pages already exist on the responsibilities of an Area Manager, how to use Cartouche, identify and solve map problems, set standards for labeling roads, and a general FAQ. The purpose of this page is to help Area Managers & others design maps that work best for the end-user--the driving public--while minimizing the amount of (re)work you have to do because of common mistakes or subtle limitations of the tools.

At the moment, I am taking suggestions via PM for content for this page: topic suggestions are good, but links to insightful forum conversations, or even links to other Wiki pages, would be better. I won't be able to incorporate every suggestion, but I will appreciate all of them.

Overall Goals

Usability

When it comes to the map, the first & foremost goal of editing is to provide the driver with a map that is easy to follow on a small display, and to produce sensible verbal instructions when (and only when) they are needed.

Simplicity

It is not a goal to model the physical roadway lane-by-lane. Doing so often leads to unnecessary complexity--which means a cluttered map, confusing verbal directions, and lots and lots (and lots!) of extra map maintenance.

Retention

As a result of people driving over them, road segments retain certain information (e.g., average speed) that is used in route optimization. When a segment is deleted, that information is discarded. Given a choice between deleting a tangle of segments and creating new ones in their place, vs. untangling them and reusing them, it is often better to "recycle".

In Practice

When to Split a Two-Way Road

How to "Un-Split" two One-Way Roads

Sorry to say it, but there is no easy way to merge two one-way roads back into a two-way road--which is why you should always give a lot of thought before splitting a road in the first place. And then think again.

When to Use Ramps in an Intersection

When to Create a Roundabout

In the author's editing and driving experience, once you learn how to create a roundabout in Cartouche, it is always the right time to replace an ad hoc traffic circle (built from regular road segments) with a proper roundabout. The voice cues produced by an ad-hoc circle can be terribly misleading, and the client display almost always looks unprofessionally sloppy. Replacing this with a roundabout is an instant, orders-of-magnitude improvement on both counts.

Cartouche Caveats

Every tool, however good, has its limitations, and Cartouche is no exception. For general editing, what you see is usually what you get, and if you read the copious online documentation in advance, you will be able to make sense of (and extricate yourself from) most situations that you run into when editing the map. But there are a few things to watch out for, that can result in a lot of extra work for you if you miss them.

Editing Multiple Segments

Directionality & Locking

The Turn Restrictions Layer is Broken

Until they fix it, just leave this layer off and use the Highlight Connectivity feature instead.

Connectivity

Just because two roads are touching where there is a junction, don't assume they are connected. Because you have "Highlight Connectivity" turned on (see above), you should notice pretty quickly that a segment is not connected. To fix, either:

  • Highlight the disconnected segment and the one to which it needs to connect, in from-to order where one-way roads are involved, and use "Connect roads in order of selection" (or the 'c' keyboard shortcut)

or

  • add a junction on top of the existing junction. The new one will replace the old one. Most of the time you will want the "Allow all turns" mode on, but sometimes when working with one-way roads it is easier to turn that option off and enable turns individually.

Reducing Junctions / Consolidating Segments

You will often see junctions in the middle of roads, where there is no intersection. These "extra" junctions are often the result of editing attempts gone awry, and seem to be a magnet for ill-connected and incorrectly-named roads. They multiply the number of segments that you need to maintain, and I'm sure they're not helpful to the routing servers. In short, unnecessary junctions indicate problems, and should almost always be eliminated. (The only exceptions are when they mark a change of city, or when you know that you will be connecting a road there very soon.)

When deleting a junction, remember that the segments on either side of the junction have to match road type, name, city, state, and have compatible directions. If both segments are two-way, or one-way in the same directions, it will work. If they are both "no entrance", it will fail. IMO this is a bug; just remember to change them to two-way beforehand, and then change the consolidated segment back to "no entrance" afterward.

After the junctions are removed, you may need to adjust the consolidated segment's geometry to account for the missing junctions.

New Roads

Recorded via Client

Once you start editing a road, it changes from red (a new road) to the colour of a road type (by default a white street) and will then appear on the next update of the Live Map which will go out to all Waze users.

So it is less than helpful if you do an incomplete job. At least if the road is red, then someone else knows that it needs work. If it is white, perhaps even with a street name, then it may look correct. But Waze may not realise it is driveable.

Follow these simple steps, as best you can, and get it right the first time. Map Editing explains how to carry out these steps.

  1. Align the geometry of the road to the aerial image unless that is not appropriate in your area
  2. Enter the correct name and road type for your road, following the standards for your country
  3. Make sure the road has the correct directionality. Most roads should be Two Way.
  4. Add junctions where the road intersects with other roads. By default tick "Enable all turns". Restrict any turns that are not allowed. If a junction appears, just add a junction over the top. Chances are it does not have all turns enabled. Waze automatically handles turn restrictions for one way roads.

Roundabouts

Even though a proper roundabout (i.e., produces "at the roundabout..." verbal cues) can only be created in Cartouche, when it is first created, the segments are configured as new roads. They will need to be edited as above before they will become part of the live map.