Mapping intersections History

Revision as of 10:53, 29 August 2021 by LostInMyMaps (talk | contribs)
This page is now a final draft and has entered a review period for feedback. This page will go live on 13 September 2021. Please discuss this page with your peers and leaders, and share your feedback with the community. If you spot any typos or errors, please feed them back to LostInMyMaps.

In line with our Revised Waze Editing Philosophy, our mapping standards have changed in 2020. For more information, see new technology, new mapping standards.

Exits, forks and splits

Remove micro-doglegs

Micro-doglegs at intersections have previously been used to force an override of voice prompts or lane guidance. They have now joined the list of <Banned map hacks> as they do not represent the reality and degrade the snapper intelligence. If you see these, please remove them immediately and replace them with respective features.


How to fix broken doglegs

Where two roads separate and continue to run parallel with each other, a large obtuse angled dogleg should be mapped:

Where two roads drift apart, the dogleg should be removed:

Below are some examples of what to look out for and remove:




Where should exits, forks and splits start/end?

Lanes have often been mapped to be long in order to provide drivers with advanced notice of maneuvers ahead. The position of Waze is that this practice is to be avoided, and corrected wherever it is found on the map.

In the below example, if the GPS drifts (seen in green), the snapper may be fed data which could see the snapper position the driver on an unintended route:

To completely avoid this risk and ensure snapper as the best information fed into its intelligence, the start of the lane should commence just prior to the gore point. Please ignore the fact that a dogleg is present in the below example - these screenshots are from a live presentation Waze made to the community.

The start of exits, forks, splits and turn/slip lanes should occur just prior to the gore point; just prior to the point the driver can legally perform the maneuver. The dogleg does not need to initially align with the centre of the new lane:

Necks on roundabouts

For very large roundabouts, in the scale of 100m in diameter, where there is a clear separation of GPS tracks in two-way direction, a ‘V’ is needed for the neck of the roundabout.

If the road leading to the roundabout is already divided because it meets the requirements to divide the road, then the divided road can connect to the roundabout at different points.

Dedicated slip/turn lanes

When should slip/turn lanes be mapped?

There are of course intersections circumstances where the mapping of turn lanes is required.

Snapper is smart enough to know that drivers do not turn at 90 degree angles. It does this by expecting a divergence of the driver will occur approximately between geometry nodes of an intersection when they take turns. This action feeds into snapper’s intelligence, along with all the other sensor data, to help predict the driver’s future position.

That said, snapper is still flexible though. Case in point, Waze indicated the following example was still fine without slip lanes:

Slip lanes become much more valuable when there are geometry nodes close to the intersection, after the turning lane has already begun. See the following example:

The second scenario of value is where there are very large islands, or traffic islands that force traffic to be in the turning lane earlier than normal:

Australia’s position on dedicated slip/turn lanes

Australia has a different position on these lanes than other countries, which we have attempted to explain as follows. It is important Australian editors understand the difference as it is strongly enforced by country management.

Below is a simple hash junction without the slip lanes mapped and it works perfectly. The fact is, snapper is smart enough to know that drivers do not turn at 90 degree angles. Adding the three slip lanes seen in the picture below will not provide any value to the driver while creating more work for editors to implement and a lot of ongoing work to maintain it.

When we refer to the <Revised Waze Editing Philosophy>, there is a point that we should map “representative of reality”, but the biggest rationale for that is doing otherwise may negatively impact snapper and thus the driving experience. But this is not the case here.

Let us consider for a moment what it would entail to add three slip lanes here:

  1. Many new segments would be needlessly created.
  2. With slip lanes, this becomes a complex junction, meaning it is a candidate for a junction box as queuing traffic times would not be measured correctly. Junction boxes lock every segment contained, meaning now unless you’re an advanced editor, you will not have permission to change anything in this junction.
  3. Australia is a small editing community and has a limited supply of advanced editors.
  4. Lane guidance cannot be accurately added to represent the reality of the intersection, which degrades the driver experience.
  5. Maintenance of this intersection has compounded. It is now harder and more restricted. You need to be an advanced editor to remove the junction box and then update many more segments and their respective turn restrictions before the junction box is reapplied.
  6. There are now dozens of points of failure which take only a single small error for the intersection to give the driver a poor experience.

Again referring to the <Revised Waze Editing Philosophy>, we are instead following the principle of “simplicity”, to “avoid unnecessary complexity and clutter because it increases the risk of introducing errors, maintenance, and the learning curve (making it harder for new editors to get involved).”

This and the hundreds of thousands, if not millions, of intersections like it in Australia work perfectly and we like them just the way they are. If intersections are found with incorrectly mapped slip lanes, they will be removed.