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A vibrant Seattle through transportation excellence Interim Director, Goran Sparrman







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Bike Facilities

Bike Boxes | Buffered Bike Lane | Sharrows | Green Bike Lane | Bike Dots | Loop Detectors | Two Stage Left Turn Box | Advisory Bike Lanes

Bike Boxes – Let’s Get Behind It

The bike box is an intersection safety design to prevent bicycle/car collisions. It is a painted green space on the road with a white bicycle symbol inside. In some locations it includes a green bicycle lane approaching the box. The box creates space between motor vehicles and the crosswalk that allows bicyclists to position themselves ahead of motor vehicle traffic at an intersection.

How to use bike boxes if you are …

A Cyclist

When the light is red or turning red, enter the bike box along the bike lane. Once you are in the bike box, position yourself according to the direction you are intending to go.

Turning left: Move to the left of the bike box and signal that you’re turning left.

Going through: Position yourself in front of the through lane.

Turning right: Move close to the right edge of the roadway and signal that you’re turning right.

A Motorist

When the signal is red, you should stop at the stop line marked on the road. The stop line will be accompanied by the following sign:

Turning right on red will be prohibited at the following intersections:

  • Pine Street eastbound at 12th Avenue
  • Madison Street eastbound and westbound at 12th Avenue

The video was created for SDOT by Max Hohlbein and Revolution Studios as part of The Art Institute of Seattle’s Winter Quarter 2012 Video Production Class.

See a how to use a bike box video from Portland

Evaluation of bike boxes at Signalized Intersections


Buffered Bike Lanes

A BUFFERED BIKE LANE provides a striped cross-hatched area between bicyclists and motor vehicles. SDOT installed a buffered bike lane on a section of E Marginal Way S in 2009. A buffered bike lane is also being designed for 7th Avenue, with installation likely in 2010.

Buffered Lane



Shared Lane Pavement Marking a.k.a Sharrows

Shared lane pavement markings (or “sharrows”) are bicycle symbols carefully placed to guide bicyclists to the best place to ride on the road, avoid car doors and remind drivers to share the road with cyclists. Unlike bicycle lanes, sharrows do not designate a particular part of the street for the exclusive use of bicyclists. They are simply a marking to guide bicyclists to the best place to ride and help motorists expect to see and share the lane with bicyclists.

What do sharrows mean for motorists and bicyclists?

• Expect to see bicyclists on the street
• Remember to give bicyclists three feet of space when passing
• Follow the rules of the road as if there were no sharrows

• Use the sharrow to guide where you ride within the lane
• Remember not to ride too close to parked cars
• Follow the rules of the road as if there were no sharrows



Bike Dots are pavement markings for signed bicycle routes. Unlike sharrows, bicycle dots are not intended to provide guidance on bicycle positioning but are a tool to provide wayfinding.

Bike Spot


Green Bike Lanes

Motor vehicles should yield to bicyclists in green bike lanes. Green bike lanes highlight areas where bicycle and cars cross paths. Bicyclists should be alert and look for motor vehicles crossing green lanes.

Green Lane


Loop Detectors

LOOP DETECTORS tell the signal when a motor vehicle or bicycle is waiting for the light to turn green. Bike-specific pavement markings indicate where to position the front wheel in order to change the signal.

Loop Detector Marking


Safer Turns— Two Stage Left Turn Box

A two stage left turn box offers people riding bikes a safer way to turn at multi-lane signalized intersections and helps create predictability for those driving. A green bike box designates a space in front of cars that a bicyclist can wait during a red light. Signs are installed by each bike box to explain how it works. Please note—if a bicyclist feels comfortable making a left turn from  the driving lane instead of using the green box, that is okay.

Instructions for using the two stage left turn box:


  • Move into the green bike box while the traffic signal is green
  • Turn your bike in the direction you will be going and wait in the box while the traffic signal is red
  • When the traffic signal turns green, move forward across the intersection


  • Stop behind the crosswalk/stop bar when the traffic signal is red
  • When the traffic signal turns green, move  safely through the intersection as usual , with  bicyclists going first
  • If right turns are allowed, wait until the light is green and bicyclists  have passed – no right turn on red

Advisory Bike Lanes

Bike lanes can provide for increased safety and encourage more people to try bicycling. However, here in Seattle we are often faced with roads that seem too narrow to add them. One solution is to use advisory bicycle lanes. A road with advisory bicycle lanes operates as two-way street with no painted center lane.  A painted dotted line and sharrows (bicycle symbols to guide people riding bikes and remind drivers to share the road) are used to highlight the bike lanes. Because the line is dotted motorists can enter the bike lane to overtake other vehicles when no people riding bikes are present.
Instructions for using advisory bicycle lanes:

When you bike:

  • Be more prepared for a motorist to enter the bike lane than on typical streets
  • Always use caution and assume merging motorists do not see you

When you drive:

  • To safely meet an oncoming motorist you are allowed to merge into the bike lane. However, you must first yield to bicyclists
  • Even though the travel area for cars is narrow, it is still a two-way street

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