Simple lane guidance works well for in many places, but not all of them. Far lanes were developed in order to provide editors greater control over unusual and complex lane situations.
Far lanes can be added by rank 4 and higher editors. They can be added to the far turns in junction boxes (known as far lanes phase 1, FL1), and in paths (known as far lanes phase 2, FL2). Although junction boxes and paths have some differences, far lanes work identically whether in a path or junction box connection.
They can enhance lane guidance in at least one of two ways, and often both at the same time.
Combined
Similar to the heuristics used to combine the lane guidance for separate turns through H and # intersections, far lanes can be used to ensure that a complete lane picture is shown at every turn through an intersection. This is especially useful where an intersection has at-grade connectors, or its geometry is skewed too much from perpendicular to meet the requirements for lane-combination heuristics to work.
Preferred
Preferred lanes show drivers that they should use a particular lane or lane(s) that are a subset of the lanes involved in a turn. For example, there may be two lanes that turn left at an intersection, and then the two lanes split immediately in two different directions. If a driver's route is to turn left, then turn left again, the driver should be given only the leftmost lane of the turn.
50-meter rule
Far lanes are only combined for an intersection, or "pushed" past the first node to the next turn, if they meet certain criteria. These are:
- No turn instruction may be given at the first node.
- The distance to first turn that has an instruction must be less than 50 meters (164 feet).
- No lane guidance may be present on the segment immediately before the instruction.
This is a generalization of the behavior of the heuristic lanes behavior for H and # junctions, but with less restrictions (no turn angle requirements) and better control by editors. If far lanes are pushed, any visual turn instruction, TTS or voice prompt set on the far turn is also pushed to the location of the next turn. This can
If the criteria for the 50-meter rule are not met, and there is no full turn instruction on the first node of the junction box or path connection, the far lane(s) will be displayed at the first node with a continue straight text under them, just like "view only" straight lanes.
Guidance
Use far lanes when necessary to provide one or both of the following benefits:
- More complete lane guidance at multi-node intersections that heuristics cannot combine.
- More specific, preferred lane guidance through a junction based on a later turn.
For combined lanes the question simply revolves around what constitutes a "single intersection." If unsure, check street view and imagine if you as the driver would see all the roads meeting together as one large intersection or not. Check lane signage and pavement markings and try to match Waze to what the driver sees. The basic cases are # or H intersections, intersections with at-grade connectors, and combinations of the two.
For preferred lanes, the easy cases are easy: Preferred lanes should be set for any multi-lane movement where you're already getting an instruction and where the best lane to choose at the movement depends on which movement you're going to make next. Any time you have two or more lanes going through the same turn, exit, or keep, you should consider preferred lanes. Look for applicable later movements which are close enough to make a difference in which lane to be in earlier. A good yardstick is "within about the next minute" for whether a later movement is close enough to need preferred lanes. This means about 1 mile on a 60-mph freeway, much shorter at surface speeds; use your best judgment.
but the more interesting questions around #1 preferred lanes are about how you use them in places where you wouldn't have otherwise received an instruction. for example, one i think of as "not that right lane!" if you have 2 freeway exits on the same side about a mile or less apart, and the first one has an exit-only lane of any kind, then a view only straight at the first exit for the second exit's lane(s) can be very helpful and if the second exit is multi-lane, you can even use that view-only to direct people into the correct lane for the 2nd exit this example has both - https://waze.com/en-US/editor?env=usa&lat=29.99653&lon=-90.14143&zoomLevel=17&segments=506996365 so what the view only is saying/doing is not only showing the correct lane for the 2nd exit as of the 1st exit, but also suppressing the "use the right lane to" part of the TTS instruction for the 2nd exit until you actually pass the 1st exit you can also do that stuff at the street scale... this example looks a little overboard but why not? https://waze.com/en-US/editor?env=usa&lat=29.96065&lon=-90.18111&zoomLevel=17&segments=20938270 if you have a series of hard to predict turn-only lanes then drivers can use the help