Proposed features/Buffered bike lane

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A buffered bicycle lane on downtown Portland's Southwest Stark Street
Cycleway Buffer
Status: Proposed (under way)
Proposed by: grant.humphries
Tagging: cycleway:buffer=yes/right/left/both
Applies to: Way
Definition: The purpose of this key is to indicate the
presence of buffers on bicycle infrastructure and
more specifically to create a way to distinguish
standard bicycle lanes from from buffered bicycle
lanes.
Rendered as: This feature should be rendered as a casing on
streets that have this infrastructure characteristic.
A buffered bicycle lane, for example, should have
a double casing, one representing the buffer and
one representing the bicycle lane.
Draft start: 2012-02-13
RFC start: 2012-02-19
Vote start:
Vote end:

Definition

Cycleway buffers most commonly appear on bicycle lanes. A buffered bicycle lane is a cycle track that lies within the roadway and is separated from motor vehicle traffic by a stripe painted on the road with an additional stripe painted beyond its outer edge (on one or both sides) that indicates the beginning of the motor vehicle lane or parking area. The space that is created between the bike lane and the motor vehicle lane/parking spaces (which is often filled with a series of diagonal stripes) is not intended for travel by any mode, but rather exists as buffer to create greater separation between bicycles and autos. Buffers on other bike infrastructure types work in much the same way, they create additional space between motor vehicles and bikes.

Rationale

Bike lanes and buffered bike lanes are different in both their physical characteristics and in the experience that they offer to bicyclists, but the two are generally tagged in the same way (as cycleway=lane) by the OSM community. The distinction between these two lies in that the buffer that gives a bicyclist extra separation from designated motor vehicle areas. This feature can be particularly useful when bike lanes are narrow in width or on high traffic, high speed, or winding streets all of which can cause cyclists to stray from the center of their lane. The buffer can also provide further severance from car doors opening from parked vehicles. The addition of the cycleway:buffer=* key will allow routing engines to treat streets with buffered bike lanes (or other bicycle infrastructure types with buffers) differently than their unbuffered counterparts when planning trips. The values that are associated with this key present the opportunity to include detail that describes exactly where the buffer is located, and thus creates the option of valuing the buffer differently when routing based on its location.

Examples

A prominent example of a buffered bike lane in the United States can be found on a pair of one way streets that run through downtown Portland, Oregon. Southwest Stark Street and its couplet Southwest Oak Street have buffered bike lanes from Southwest Naito Parkway west to West Burnside Street and Southwest 9th Avenue respectively. This type of infrastructure is growing in popularity and there are hundreds if not thousands worldwide.

Values

yes
Indicates that a cycleway has a buffer. Specifying the location of the buffer with one of the three values below is preferred. This value should only be used in the rare case that the mapper is sure that a cycleway has a buffer, but unsure of the buffer's position relative to the cycleway.
right
Indicates that there is a buffer on the right side of a cycleway (and not on the left side), with the left and right directions determined based on the directionality of the way on which this tag appears.
left
Indicates that there is a buffer on the left side of a cycleway (and not on the right side).
both
Indicates that there are buffers on both the left and right sides of a cycleway.

Tagging

The primary purpose of this key and it's most common use is to distinguish buffered bicycle lanes from standard bike lanes. Since this is the case it will most commonly be tagged in conjunction with cycleway=lane as seen below:

cycleway=lane 
cycleway:buffer=*

The cycleway:buffer=* key can also be used coupled with other cycleway=* values such as cycleway=opposite_lane and cycleway=share_busway, if these bicycle infrastructure types have buffers, but it should not appear unless a cycleway=* tag of some kind is present.

Rendering

proposed rendering of buffered bicycle lane

In the image at right I have designed a potential rendering scheme for buffered bicycle lanes. Note that there are two casings around the lines that represent roads. The inner casing is dashed (similar to diagonally striped buffers that surround bike lanes) and bright green (the color often used for bicycle pavement markings), the outer casing is a saturated blue (a color typically associated with bicycles in OSM).

Features/Pages affected

Comments

See Discussion page