User:Airchair/drafts/WhenToSplit

When to Split a Two-Way Road or Merge a Two One-Way Roads

Generally, a road should be a single two way road unless it meets ALL of the requirements for dividing a road. When initially reviewing whether to divide or "un-divide" (merge back together) a roadway, consider these points first:

1. The default representation for any roadway is a single 2-way segment, even if the physical roadway is divided. Dividing a roadway carries with it the burden of proof that the change will improve the usability and/ or simplicity of the Waze map.
2. If a road is currently working with no problem reports, consider leaving it as is.
3. Prior to splitting a road, send a PM to one of the State or Country Managers or Country Coordinators.
4. Try to avoid switching roads back and forth between being divided and 2-way. For example, if most of the road is clearly divided and only parts would be considered a single two-way road, consider leaving it all divided. If only a small portion seems better off divided, consider keeping it all 2-way.

A road may be divided when ALL of the following conditions are met:

• GPS tracks show a clearly definable and continuous gap (blank area) between the color-by-azimuth arrows at the 100m/500ft zoom level,
• Multiple houses or businesses with no off-street parking are located directly on the street but are not accessible from the opposite direction of travel due to lengthy dividing median, obstruction, or traffic control signage, or
• U-turns are required to properly make turns from public driveable road types that are blocked by a median.

A road should not be divided when:

• There is a curb or non-driveable median less than 5m wide between lanes of travel (see exceptions above).
• The non-driveable median is interrupted by a cross segment at most intersections.
• There is a center turn lane (any width) between directions of travel. Dividing this type of road creates problems when people turn from the middle lane because there is no road for the navigation to follow.
• It is possible and legal to make a right turn/u-turn everywhere along the road
• The objective is solely for visual appearance or to make the road match another visual source like Google Maps. MATCHING GOOGLE (or any other map product) IS NOT A REASON.

Remember that dividing and undividing roads each comes with its own set of problems. Each situation is unique and some issues may be more manageable with a single two-way road, and some may work fine with a divided road. Consider every aspect of routing, and carefully examine each junction before dividing or undividing. Regardless of whether you're dividing or undividing, remember that you might cause more problems than you solve and you might have to put it back the way it was before. Also remember that dividing and undividing each cause loss of some traffic data, which can result in poor Waze routing.