Shared Lane Marking: Difference between revisions

Latest revision as of 12:11, 19 May 2026

A shared lane marking, also known as a sharrow is a lane marking depicting a bicycle intended to inform road users where bicycles are supposed to ride within the lane.

Common reasons for their use include

Communicating to drivers that cyclists have a right to use the road
Encouraging cyclists to use a specific part of the lane, such as the edge or center (taking the lane).

Recommended Use and Limitations[edit | edit source]

Shared lane markings can be helpful as part of a Bike Boulevard or a shared space by assisting in communicating where bicycles are meant to ride within the lane.^[1]^[2] See the articles on bike boulevards and shared spaces for specific guidance on where and when to apply shared lane markings.

Shared lane markings have historically been used on roadways with high traffic volumes or high speeds as a form of bikeway. This solution is no longer considered acceptable by most agencies, since it is generally not accessible to riders of all ages and abilities (AA&A).

According to the 2025 NACTO Urban Bikeway Design Manual, roadways where bikes and motor vehicles share a lane should have an AADT of less than 2000 and a target speed of 20 mph or lower, as part of a bike boulevard or shared space. The guide explicitly states that shared lane markings on their own are not sufficient to create an AA&A bikeway.

The 2024 AASHTO Guide for the Development of Bicycle Facilities states that sharrows should only be used as part of a bicycle boulevard or shared space. "By themselves, shared lane markings are not considered a bikeway because they do not change the geometric or operational conditions of the roadway to improve comfort and safety for bicyclists." {TODO cite 9.3.3. of bike guide)

TODO crow manual

TODO summary.

References[edit | edit source]

↑ National Association of City Transportation Officials. Urban Bikeway Design Guide(3rd ed.). Island Press, § 3.2.1. ISBN 978-1-64283-384-3.
↑ National Association of City Transportation Officials. Urban Bikeway Design Guide(3rd ed.). Island Press, § 3.2.2. ISBN 978-1-64283-384-3.

[1] National Association of City Transportation Officials. Urban Bikeway Design Guide(3rd ed.). Island Press, § 3.2.1. ISBN 978-1-64283-384-3.

[:0-2] National Association of City Transportation Officials. Urban Bikeway Design Guide(3rd ed.). Island Press, § 3.2.2. ISBN 978-1-64283-384-3.

[1]

[2]

@@ Line 7: / Line 7: @@
 == Recommended Use and Limitations ==
-Shared lane markings can be helpful as part of a [[Bike Boulevard]] or a shared space by assisting in communicating how bicycles are meant to use the infrastructure. Simply painting sharrows does not address the fundamental bike safety and comfort issues that plague most roadways.  Meeting the needs of cyclists of all ages & abilities requires reducing the number and severity of conflicts between bicycles and motor vehicles.
+Shared lane markings can be helpful as part of a [[Bike Boulevard]] or a shared space by assisting in communicating where bicycles are meant to ride within the lane.<ref>{{cite book|title=Urban Bikeway Design Guide|edition=3rd|date=2025|publisher=Island Press|author=National Association of City Transportation Officials|isbn=978-1-64283-384-3|at=|page=|section=3.2.1}}</ref><ref name=":0">{{cite book|title=Urban Bikeway Design Guide|edition=3rd|date=2025|publisher=Island Press|author=National Association of City Transportation Officials|isbn=978-1-64283-384-3|at=|page=|section=3.2.2}}</ref>  See the articles on bike boulevards and shared spaces for specific guidance on where and when to apply shared lane markings.
-Shared lane markings can be used as part of a low speed, low AADT roadway, such as a bike boulevard or shared space, to mark where bicycles are supposed to ride within the lane<ref>{{cite book|title=Urban Bikeway Design Guide|edition=3rd|date=2025|publisher=Island Press|author=National Association of City Transportation Officials|isbn=978-1-64283-384-3|at=§3.2.1 Shared Spaces, "Design Guidance: Markings"|page=100}}</ref>.  Even in these situations, however, a dedicated vertically separated bikeway or constrained bike lane is preferable if space allows<ref>{{cite book|title=Urban Bikeway Design Guide|edition=3rd|date=2025|publisher=Island Press|author=National Association of City Transportation Officials|isbn=978-1-64283-384-3|at=§3.2.3 Constrained Bike Lanes, "Designing for All Ages & Abilities"|page=129}}</ref>.
+Shared lane markings have historically been used on roadways with high traffic volumes or high speeds as a form of bikeway.  This solution is no longer considered acceptable by most agencies, since it is generally not accessible to riders of [[All Ages & Abilities|all ages and abilities]] (AA&A).
-Shared lane markings have historically been used on roadways with high traffic volumes or high speeds as a form of compromise bikeway.  This is no longer recommended, because these facilities are not accessible to all ages and abilities.  Design manuals differ slightly on when shared bicycle-motor vehicle lanes are appropriate, but the advice is largely the same.  According to the 2025 NACTO Urban Bikeway Design Manual, roadways where bikes and motor vehicles share a lane should have less than 2000 vehicles/day and a target speed of 20 mph or lower. In this  case, sharrows should be applied in the center of the lane, to encourage cyclists to take the lane<ref>{{cite book|title=Urban Bikeway Design Guide|edition=3rd|date=2025|publisher=Island Press|author=National Association of City Transportation Officials|isbn=978-1-64283-384-3|at=§3.2.2 Bike Boulevards, "Design Guidance: Markings"|page=109}}</ref>. The 2024 AASHTO Guide for the Development of Bicycle Facilities confirms this by stating that sharrows should only be used as part of a bicycle boulevard or shared space {citation needed}.
+According to the 2025 NACTO Urban Bikeway Design Manual, roadways where bikes and motor vehicles share a lane should have an [[wikipedia:Annual_average_daily_traffic|AADT]] of less than 2000 and a target speed of 20 mph or lower, as part of a bike boulevard or shared space.  The guide explicitly states that shared lane markings on their own are not sufficient to create an AA&A bikeway.
+The 2024 AASHTO Guide for the Development of Bicycle Facilities states that sharrows should only be used as part of a bicycle boulevard or shared space.  "By themselves, shared lane markings are not considered a bikeway because they do not change the geometric or operational conditions of the roadway to improve comfort and safety for bicyclists." {TODO cite 9.3.3. of bike guide)
+TODO crow manual
+TODO summary.
+== References ==