Turn segments and connector roads

Turn segments

Turn segments, commonly referred to as slip roads, are segments between two connecting roads that bypass the direct intersection of the roads. They are the preferred route, or perhaps the only valid route, for turns between the roads (as turning from an intersection is not permitted when there are turn segments to avoid the intersection).

For example, in the US this would be a segment that would allow a vehicle to take a free right-turn without having to go through the intersection. The small segment next to the island of a channelized slip road would also fall under this category.

  • Slip roads exist between intersecting roads (as opposed to ramps, which exist between non-intersecting roads).
  • Slip roads do not have names or addresses.
    • If a slip road has a different name from the route it's derived from, it should be left as a normal road.
    • If a slip road contains address information for the route it's derived from, the address information should be copied to the main route.
  • If a slip road or turn segment connects directly to a ramp, it should be considered part of the ramp and given Ramp usage.
  • Turn segment or slip road priority should be assigned according to the priorities guidelines.
  • Left turn lanes should not be added as separate linear features unless the intersection is designed as a Displaced Left Turn or Continuous Flow Intersection. If traffic entering a road is prevented from accessing a non-displaced left turn lane due to a physical or painted barrier, you can Report a Problem to ensure that directions will route drivers correctly.
    • A Displaced Left Turn or Continuous Flow Intersection is a specific type of intersection design that allows left turning traffic to bypass the road intersection, as seen in the image below. These segments can be added as separate linear features and should be given the Turn Segment usage.

Turn lanes such as "jughandles" that are physically separate from a road's through traffic should have the turn segment usage. In the image below, the jughandle turn segment is highlighted in pink. The jughandle replaces a left turn for drivers travelling east, so the segment is given the turn segment usage.

To add a turn segment:

  1. Draw a road using a line tool.
  2. Select Turn segment from the Segment usage drop-down menu.
  3. Select the appropriate priority.
  4. Click Save.

 

Connector roads

Connectors are short road segments between split roads that allow U-turns or access to specific destinations. These are independent segments which do not provide connectivity for crossroads on the split road. Connector roads should not have any Segment usage assigned.

In the screenshot above, the road segment between markers A and B is a connector road.

The priority of connector roads should be set according to the priorities guidelines. Usually, connector segments between freeways are not used by general traffic. In such cases, mark the priority as No auto traffic; please note that these No auto traffic segments are not used for driving directions.