Roundabouts Best Practices - TelenavMapping/Telenav_mapping_team_practices_and_workflow GitHub Wiki

A roundabout is a road junction where the traffic goes around a non-traversable island (or a void in case of elevated roads) in the middle, and the traffic in the roundabout has right of way. Roundabouts can have any size from tiny to huge with several lanes.

highway=*

• It should be the same as the connecting roads. If there are several roads of different importance connecting to the roundabout, the one with the highest ranking should be used for the highway tag.

junction=roundabout

oneway=yes

• It is implied. Though it is not wrong to add it explicitly, it is not needed.

name=*

• Should only be used if the junction itself is named independently and differently from the roads crossing it.

example:junction=roundabout

• Add 3 points around the roundabout approximately in the middle of the street, select them and press Shift+O to create a circle.

• Check the neighboring ways to verify the road classification and add the same highway tag the roundabout.

• Add the junction=roundabout tag on the created circle.

• Update the geometry of the roads crossing the roundabout and intersect them with the roundabout in separate nodes, thus routing apps can safely recognize that a section of the roundabout has to be driven through.

• If it is the case, also check if there are relations passing thru the roundabout and update them accordingly. This way, you make sure that there are no relation gaps.