User:Baloo Uriza/lanes

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Logo. Feature : Baloo Uriza/lanes
One example for Feature : Baloo Uriza/lanes
Description
To tag individual lanes of a road together with their distinctive properties.
Tags

lanes=*, turn:lanes=*, destination:lanes=*, access:lanes=*, ...

Combinations
*:lanes
taginfo *:lanes

Description

The subkey :lanes can be used to tag individual lanes of a road.

The similar main key lanes=* counts the number of traffic lanes, including special lanes for turning or specific modes.

Lane-specific information can be expressed on a way by suffixing the key with :lanes. This suffix is applicable to any existing <key>=<value> tag pair. The value of that tag then contains the values for each lane separated by a | (vertical bar) in left-to-right order as viewed in the respective driving direction of those lanes. If the value of a specific lane is left blank, the (possibly assumed/implicit) value of the main key without :lanes-suffix applies (the so called default value).

In the common case of two driving directions either :forward or :backward is added to the end of the key; i.e., <key>:lanes:forward describes the properties of the lanes in the same direction as the osm-way, whereas <key>:lanes:backward described the properties of the lanes in the opposite direction of the osm-way.

Please be aware that this extension covers all kinds of lanes for all kind of vehicles and is not restricted to motorized traffic.

Differences from current tagging

The current tagging excludes narrow lanes, such as those for bicycles or motorcycles. This presents some difficulties.

For consumers

Consumers can't reliably trust lanes=* to be a safeguard for botched tagging when the number of lane values doesn't match lanes:forward=*, lanes:backward=* or lanes=* as appropriate, and makes lane guidance only useful for doubletracked motorists. This alternative closes both of these gaps.

For editors

Presently most validators and the JOSM extension for lane tagging already expect lanes values to match the number of values for lane access and turn lane tagging. Making these always match prevents confusion for everyone. This also obviates that tagging lanes on cycleways is a go.

Examples

In principle every tag used to describe properties of a road can be extended by the :lanes suffix when its value depends on the lane. Following list gives an overview of potentially useful combinations and a short description when they might be needed:

Road property Lane specific key Description
access=* hgv:lanes, psv:lanes... Useful if access depends on the lane: For example lanes can be restricted to buses (psv:lanes) or forbidden for heavy good vehicles (hgv:lanes).
maxspeed=* maxspeed:lanes Can be used for roads where the maximum allowed speed depends on the lane. See example below.
turn=* turn:lanes Allows description of designated turn lanes or which lanes will merge in the direction of travel. See detailed examples below.
change=* change:lanes Allows description of possible lane changes using the lane marking on the road.
minspeed=* minspeed:lanes Useful for roads where some lanes require a minimum speed or where lanes have different minimum speed.
surface=* surface:lanes Lane dependent surfaces, for example if there is cobblestone on the outer lane
destination=* destination:lanes While the road specific key describes the direction of the highway by using the name of the city the highway is heading to, the destination:lanes allows tagging of cities when sign-posted for individual lanes. See destination=* for examples.
width=*, maxwidth=* maxwidth:lanes, width:lanes Where necessary, the width of lanes can be tagged. As usual maxwidth:lanes would describe a legal width restriction and width:lanes the actual width of a lane.
maxheight=* maxheight:lanes A height restriction may vary from one lane to another if the road passes beneath an overpass that is inclined or arched.
hov=* hov:lanes If one or more lanes of the road are restricted to high-occupancy vehicles (typically vehicles with 2+ occupants, although this varies by jurisdiction). Most useful if entrance/egress is permitted at any point along the route; if entering or exiting the HOV lane(s) is only permitted at certain locations, modeling the HOV lane(s) as separate ways is preferable.
payment=* payment:<payment_method>:lanes In cases where a road toll has a special lane which segregates drivers by a certain payment method, it's possible to use the lanes scheme.

For example: a toll booth area with several normal lanes (where a driver must pay with cash or a card) and a special lane, usually on the far right or far left, where it's not needed to stop nor pay on the spot. One of such cases happens in Portugal, with Via Verde. In such cases, the following tag can be used: payment:via_verde:lanes=no|no|only. (this means the highway has three lanes and the far right lane only allows drivers that are going to pay with Via Verde.

Mapping

A highway's ways should be mapped and split exactly where the extent of a number of lanes becomes available.

The way tagged with lanes from a way approaching or leaving an intersection node should extend all the way to the intersection node, even though the physically marked lanes do not because it is an intersection.

Street

Here, a residential street transitions from 2 lanes on the right to 3 lanes approaching the intersection.

There is a turn lane transition area marked with dashes where the lane begins to form, however, since it is not fully formed, the way that includes three lanes does not extend to include it.

The way only extends to where the full 3 lanes are present and available to use. In this example, this is also marked by start of the solid line dividing the turn lane and the through lane.

Tagging a left turn lane in iD.png

See on OSM

Complex street

Example will be added.

Intersection of dual carriageways

Example will be added.

Parallel highway and highway link

Example will be added.

Different maxspeed per lane (with/without default values)

A simple lane dependent maxspeed example with road sign (one-way street and a general speed limit of 100 assumed):

CH-Hinweissignal-Anzeige von Fahrstreifen mit Beschränkungen.svg
Without the use of default values:
lanes=3
oneway=yes
maxspeed:lanes=100|100|80

Using default values:
lanes=3
oneway=yes
maxspeed=100
maxspeed:lanes=||80

Considering backward compatibility it might be preferred to tag this using default values.

Two driving directions

In the common case of two driving directions either :forward or :backward is added to the end of the key.

 lanes=6
 lanes:forward=3
 lanes:backward=3
 hgv:lanes:forward=no|yes|yes
 hgv:lanes:backward=no|yes|yes

This is a road with three lanes in each direction and heavy good vehicles are prohibited on the leftmost lane in each direction.

The lanes are viewed in the respective driving direction; i.e., hgv:lanes:forward describes the lanes in the same direction as the osm-way. The first lane-value refers to the leftmost lane in this direction. Whereas hgv:lanes:backward describes the lanes in the opposite direction of the osm-way.

Minimum speed

Road with a sign-posted minimum speed, which applies to one lane only. Can be tagged as:

Zeichen 526-31.svg
lanes=3
lanes:forward=2
lanes:backward=1
minspeed:lanes:forward=50|

Please note the final | character in the value of minspeed:lanes:forward: Because the right-most lane has no minimum speed, no value should be tagged after the lane separator.

Motorway with lanes and destinations

The following example demonstrates the tagging of a motorway.

Lanes Example vert7.png Left part: lanes=3
Right part: lanes=1
Lanes Example vert6.png Left part: lanes=2
Right part: lanes=2
turn:lanes=none|merge_to_left
Lanes Example vert5.png lanes=4 (**)
change:lanes=not_left|not_right|not_left|not_right
Lanes Example vert4.png lanes=4
turn:lanes=slight_left|slight_left|slight_right|slight_right

destination:lanes=A|A|B|B

Lanes Example vert3.png lanes=3
turn:lanes=slight_left|slight_left;slight_right|slight_right(*)

destination:lanes=A|A;B|B (*)

Lanes Example vert2.png lanes=3

turn:lanes=slight_left|slight_left;slight_right|slight_right (*)

Lanes Example vert1.png lanes=3
destination:lanes=A|A;B|B (*)

* These tags show how to add more than one value to a single lane, by separating those values with a ; (semi-colon).
** There is no physical separation between the upper two lanes and the lower ones, just a double solid line. While the editing standards recommends splitting the ways only when a physical separation is present, in many regions the ways are already split in case of a legal separation like a double solid line. In such a case both resulting ways should be tagged with lanes=2.

Crossing with a designated lane for bicycles

The following example demonstrates tagging lanes with different kinds of traffic.

Kreuzung mit Radspur.jpg
 lanes=4
 turn:lanes=left|through|through|right
 vehicle:lanes=yes|yes|no|yes
 bicycle:lanes=yes|no|designated|yes
 cycleway:lanes=no|no|lane|no

Pay attention to the value of the lanes=* key. This should be the total number of lanes for movement.

Note: Access tags, like "bicycle:lanes", depend on the country and other circumstances:
"bicycle:lanes=yes|no|designated|yes" value is result of fact that in this case bicycles are obligated to use bicycle lane in certain circumstances (e.g. as long as cyclist is not turning left or right or the cycle way is obstructed or otherwise not practicable, or the bike is too wide (e.g. trailer) and would encumber other cyclists). In other countries where use of bicycle lane is not fully obligatory for cyclists, like in Germany, tagging may be "bicycle:lanes=yes|yes|designated|yes".

Note: adding also cycleway=lane would be fine and useful in this case.

Designated Motorcycle Lanes

When tagging lanes you should be counting all lanes=*.

|___1___|___2___|_3_|_4_|

1 and 2 can both take most motor_vehicles, but lanes 3 and 4 cannot.
Motorcycles can use lanes 2, 3, and 4.
Lanes 3 and 4 are designated as motorcycle lanes.

 lanes=4
 motorcycle:lanes=no|yes|designated|designated

If there is additional signage indicating that the left two lanes are for motor vehicles and the right two are not.

 motor_vehicle:lanes=yes|yes|no|no

Editor support

JOSM

The style Lane and Road Attributes visualizes, amongst others, a variety of lane-dependent tags directly while editing, and also detects some common tagging mistakes like e.g. inconsistent number of lane-dependent values. The image below shows a oneway=yes road tagged with the keys turn:lanes=*, width:lanes=* and placement=*.

JOSM Style Road Attributes Example 1.jpeg


The preset Lane attributes helps finding and remembering all these tags.

See also