Segment geometry

This page gathers the geometry rules for editing segments in Switzerland: micro-segments, loops, dead ends, U-turns, narrow streets, private driveways, transitions and offset roads.

Micro-segments

Avoid micro-segments

A segment must be at least 5 meters long for optimal operation. Shorter segments prevent efficient route calculation.

Roundabouts are excluded from this rule: their segments can be shorter.

Loops

A loop must be made up of at least 3 road segments. In other words, two segments must not share two junctions in common.

2-segment loop

A 2-segment loop creates routing errors ("same endpoint drivable segments"). Add a junction node to split it into 3 or more segments, without creating a micro-segment.

Large loop

If the loop is very large, add a walking trail or an alley to prevent it from being deleted by accident.

Dead ends

Do not map loops or turnaround roundabouts. Simply extend the end of the segment to the farthest point reachable by driving.

• Place the final junction node near the end, at the center of the roadway.
• The distance from the node to the ends matches the distance to the edges.
• For a central island, place the node outside the perimeter of the island.

Reminder

If, when standing at the end of the road, you clearly see a simple dead end, do not create a loop.

U-turns

Set a U-turn maneuver to green (allowed) only if:

1. a two-way segment connected to a one-way creates a dead end, or
2. the maneuver can be done without reversing, is legal and is indicated by a marking, a sign or a traffic light.

Narrow street / Alley

The "Narrow street / Alley" type (type 22) is only used if the road is two-way, longer than 50 meters and only wide enough for a single standard vehicle.

Do not use for

• one-way streets;
• short bridges and passages;
• dead ends;
• other road types with penalties;
• crossings that are impossible except for heavy vehicles;
• permanent traffic lights;
• narrowings meant to slow down traffic;
• entire villages.

Private residential driveways

Do not map individual private driveways, unless:

• the road serves at least 2 dwellings, or
• the road is particularly long, or the dwelling is more than 100 meters from the road, or
• not mapping it would cause routing problems.

Transitions and offset roads

Transitions

A transition represents the absence of an intersection between two segments. It is used for:

• a road name change;
• a change in direction of travel (two-way to one-way);
• making a loop navigable.

Remove unnecessary junction nodes to simplify the map.

Offset roads

Three cases to consider:

1. Roads aligned in reality: change to a 4-segment intersection.
2. Roads almost aligned: force the junction close to 90 degrees to get the "straight ahead" instruction.
3. Genuine separation: leave the sides unaligned and maximize the length of the small segment between the roads.

Sources

• Editing rules in French-speaking Switzerland: https://www.waze.com/discuss/t/regles-dedition-en-suisse-romande/377277
• Intersections guide: https://www.waze.com/discuss/t/guide-des-intersections/377286
• Information in French: https://www.waze.com/discuss/t/informations-en-francais/377254