User:Bicycle tourer/Table with possible combinations of highways and links in confluences

Based on the definition of confluences the following table shows which types of highways can be part of a confluence and how the links are categorized. See also remarks below the table.

Merging road	Receiving road	directly or via	explanation	potential resolution
motorway	motorway	motorway_link
	trunk	motorway_link
	primary	directly, motorway_link
	secondary
	tertiary
	unclassified
	residential	<never>	Confluence means end of motorway (not a motorway exit). A residential, living-street, service-road or track cannot take the full traffic load of a motorway.	Receiving road of higher qualification? Merging road of lower qualification?
	living street
	service
	track
	cycleway	<never>	A motorway must not merge into a cycleway or footway/pedestrian, even not as a link.	<none>
	footway/pedestrian	<never>		<none>
trunk	motorway	motorway_link
	trunk	trunk_link
	primary	directly, trunk_link
	secondary
	tertiary
	unclassified
	residential	<never>	Confluence means end of trunk (not a trunk exit). A residential, living-street, service-road or track cannot take the full traffic load of a trunk.	Receiving road of higher qualification? Merging road of lower qualification?
	living street
	service
	track
	cycleway	<never>	A trunk must not merge into a cycleway or footway/pedestrian, even not as a link.	<none>
	footway/pedestrian	<never>		<none>
primary	motorway	motorway_link
	trunk	trunk_link
	primary	directly, primary_link
	secondary
	tertiary
	unclassified
	residential	<never>	Confluence means end of primary (not a primary exit). A residential, living-street, service-road or track cannot take the full traffic load of a primary.	Receiving road of higher qualification? Merging road of lower qualification?
	living street
	service
	track
	cycleway	<never>	A primary must not merge into a cycleway or footway/pedestrian, even not as a link.	<none>
	footway/pedestrian	<never>		<none>
secondary	motorway	motorway_link
	trunk	trunk_link
	primary	directly, secondary_link
	secondary
	tertiary
	unclassified
	residential	directly, secondary_link	Confluence means end of secondary (not a secondary exit). Merge into residential is seldom.	A 3 way junction between secondary and two residentials? Receiving road of higher classification (e.g. unclassified)?
	living street	<never>	Confluence means end of secondary (not a secondary exit). Nobody wants to have full size secondary traffic merging into living_street.	Merging road of lower classification (e.g. unclassified)?
	service	<never>	Confluence means end of secondary (not a secondary exit). A service road or track cannot take the full traffic load of a secondary.	Receiving road of higher qualification? Merging road of lower qualification?
	track	<never>
	cycleway	<never>	A secondary must not merge into a cycleway or footway/pedestrian, even not as a link.	<none>
	footway/pedestrian	<never>		<none>
tertiary	motorway	motorway_link
	trunk	trunk_link
	primary	directly, tertiary_link
	secondary
	tertiary
	unclassified
	residential	directly, tertiary_link	Confluence means end of tertiary (not a tertiary exit). Merge into residential is still unusual.	A 3 way junction between tertiary and two residentials? Receiving road of higher classification (e.g. unclassified)?
	living street	<never>	Confluence means end of tertiary (not a tertiary exit). Nobody wants to have full size tertiary traffic merging into living_street.	Merging road of lower classification (e.g. unclassified)?
	service	<never>	Confluence means end of tertiary (not a tertiary exit). A service road or track cannot take the full traffic load of a tertiary.	Receiving road of higher qualification? Merging road of lower qualification?
	track	<never>
	cycleway	<never>	A tertiary must not merge into a cycleway or footway/pedestrian, even not as a link	<none>
	footway/pedestrian	<never>		<none>
unclassified	motorway	motorway_link
	trunk	trunk_link
	primary	directly	There are no _links at confluences of this type. All ways which might be treated as links connecting the unclassified are classified as highway=unclassified.
	secondary
	tertiary
	unclassified
	residential	directly	This situation is unusual. Normally it's reverse: Residential/living street/service merging into unclassified	Is it a 3-way junction?
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
residential	motorway	motorway_link
	trunk	trunk_link
	primary	directly	There are no _links at confluences of this type. All ways which might be treated as links connecting the residential are classified as highway=residential.
	secondary
	tertiary
	unclassified
	residential	directly
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
living street	motorway	<never>	A living street will never merge directly into a motorway or trunk, because it contains a lot of traffic (pedestrians, playing children) which are not allowed on motorway and should be kept separate	<None>
	trunk	<never>		<None>
	primary	directly	A living street merging directly into these types of highways is unusual. Typically a living street would merge into a residential, which then connects to these highways. Anyhow, there are no _links. All ways which might be treated as links connecting the living street are classified as highway=living_street.
	secondary
	tertiary
	unclassified	directly	All ways which might be treated as links connecting the living street are classified as highway=living_street.
	residential	directly
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
service	highway	<never>	see remark 2) below	<None>
	trunk	<never>	see remark 2) below	<None>
	primary	directly	All ways which might be treated as links connecting the service road are classified as highway=service.
	secondary
	tertiary
	unclassified
	residential	directly
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
track	motorway	<never>	see remark 2) below	<None>
	trunk	<never>	see remark 2) below	<None>
	primary	directly	All ways which might be treated as links connecting the track are classified as highway=track.
	secondary
	tertiary
	unclassified
	residential	directly
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
cycleway	motorway	<never>	see remark 2) below	<None>
	trunk	<never>	see remark 2) below	<None>
	primary	directly	All ways which might be treated as links connecting the cycleway are classified as highway=cycleway. In many case it's not a confluence, but a separate cycleway merging back onto the road
	secondary
	tertiary
	unclassified
	residential	directly	In many case it's not a confluence, but a separate cycleway merging back onto the road
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian
footway/pedestrian	motorway	<never>	see remark 2) below	<None>
	trunk	<never>	see remark 2) below	<None>
	primary	directly	All ways which might be treated as links connecting the footway/pedestrian are classified as highway=footway/pedestrian. In many case it's not a confluence, but a separate footway/pedestrian merging back onto the road
	secondary
	tertiary
	unclassified
	residential	directly	In many case it's not a confluence, but a separate footway/pedestrian merging back onto the road
	living street
	service
	track	directly	see remark 1) below
	cycleway
	footway/pedestrian

Have a road A merge into road B, but some vehicle-types allowed on A not allowed on B, others allowed on both. Then this junction is for low classified A still a confluence (because vehicles not allowed can turn). Example: A track merges into a cycleway, then motor-cars cannot proceed (but they can turn); for bicycle it’s a confluence and the track merges because of this. Other example: For highly classified roads A it’s disqualifying because you do not want to have cars continuously turning on e.g. a primary. Having a primary merge into a cycleway should generate a warning.
There might be cases that low level roads (service, track etc.) merge directly into motorways or trunks (no link) to allow temporary transfer. Examples are fairs, where traffic exits and enters motorways through such connections. They are not treated as confluences, because they underly very special rules, which can change from event to event. These connections are typically directly controlled by police. The table only shows the non exceptional cases, where e.g. a track cannot merge directly into a motorway.

Links

Links are not mentioned in the table above because these cases can be determined by choosing the appropriate rows above for their non link counterpart.

Links in merging road

If there are links in the merging road, choose the highway type of the first non link of the merging road and then pick the row in the table above for this type.

Links in receiving road

There is no case that a confluence uses a link as receiving road.

Highway types covered but not explicitly mentioned

There are several ways having a highway=* tag not mentioned in the table above, but probably being part of a confluence. Here is how to cope with them.

highway=path

Whether a highway=path can be part of a confluence depends on who/what is allowed on it. If bicycle is allowed, treat it as a cycleway, if foot is allowed (without bicycle) treat it as a footway.

highway=road

Because highway=road is a temporary value which will be changed to a more specific one you can use the table above in the following way:

highway=road for receiving road
- There is high probability that it will not become a motorway or trunk, otherwise you already know that and it would be better to use highway=motorway/trunk in general
- If you expect this road as a "low traffic" road (i.e. residential, living street, service, track), pick values from those rows, as receiving road they have pretty similar behavior
- If you expect that it will become a primary, secondary, tertiary or unclassified, but can't decide yet, choose the value for unclassified
- If you already know it is a way used by pedestrians (probably together with bicycles), choose values from footway/pedestrian
- If you already know it is a way used by bicycles only, well, then you can already use highway=cycleway or highway=path with bicycle allowed
- If you really don't know, choose values from "unclassified"
highway=road for merging road
- tbd

highway=construction

A highway being under construction is tagged highway=construction. It has an additional tag construction=* which defines which highway type it will be when finished. Use the value of construction=* to determine which values to choose from the above table.

highway=proposed

A highway being proposed is tagged highway=road. It has an additional tag proposed=* which defines which highway type it will be in future. Use the value of proposed=* to determine which values to choose from the above table.

Highway types missing

There are several ways having a highway=* tag not mentioned in the table above. Here is why they are omitted at all.

highway=bridleway

A road tagged as highway=bridleway is a way for horses. It is clearly felt that this is a very special type of way, which will never be part of a confluence. Therefore it is left away.

highway=steps

A road tagged as highway=steps is a highway which cannot be used by vehicles. It's obvious that this will never be part of a confluence.

highway=bus_guideway

A road tagged as highway=bus_guideway is a special highway for buses in a special mode only. It's obvious that this will never be part of a confluence.

highway=escape

A road tagged as highway=escape has a very special usage. It's obvious that it will never be part of a confluence.

highway=raceway

A road tagged as highway=raceway is not connected to standard traffic. It's obvious that it will never be part of a confluence.

Usual vs. unsusual cases

This table assumes "usual" cases, e.g. that a motorway does not end by merging into a living_street. However there are temporary situations, where something like this might be needed, e.g. construction work, deviations. In these cases it might be necessary to tag differently from the table above.