Bike Infrastructure 101
Definitions of Bike Infrastructure
- Protected bike lanes are on-street bike lanes with a physical barrier separating the bike lane from motor vehicle traffic. The barrier can include flower planters, concrete curbs, plastic bollards, jersey barriers, and parked cars. Protected bike lanes can be either one-way or two-way.
- Neighborhood greenways are bikeways on slow speed, low volume residential streets. Greenways are more than just signed to provide bicyclists with wayfinding, greenways are engineered and designed to reduce vehicle traffic and speed on the street through speed bumps/humps, chicanes, roundabouts, curb bulbs, and priority stop signs (stops signs are removed from the bikeway and instead placed on the cross streets). Where a greenway crosses an arterial, the greenway is designed to better prioritize bicyclists and ensure their safety while crossing.
- Bike boxes are green-painted rectangles (with a white outline) at intersections that provide a safe refuge for bicyclists to either cue ahead of cars or to make a two-stage turn. Bike boxes help increase safety for bicyclists by reducing right-hand hooks by cars and by helping bicyclists navigate tricky intersections, such as where there are streetcar tracks.
- Cross-bikes are similar to crosswalks in that they warn drivers to expect bicyclists crossing an intersection. Cross-bikes are currently designed in several different ways, including parallel dashed lines with sharrows that extend a bike lane through an intersection, solid bright-green paint, and horizontal bars of bright-green paint (which is most similar to a white crosswalk).
- Sharrows are large white bike symbols on the roadway that remind drivers that bicyclists may use the full lane. The term is the combination of two words: "share" and "ROW" (or "right-of-way"). Although in Seattle sharrows are often placed toward the right-hand edge of a street, bicyclists should not feel compelled to treat the "sharrowed space" as a bike lane; instead, they should feel free to take the full lane and ride in traffic, especially when in a narrow lane next to parked cars.
Videos Explaining Bike Infrastructure
Protected Bike Lanes
Tools to design your own streets
Streetmix.net allows you to easily and quickly rearrange lanes, sidewalks and bike lanes to create your ideal street. It's become a critical tool for biking and walking advocates. Design your street >>
iamtraffic.org provides three great interactive tools to better understand the impact to the safety of people biking based on vehicle lane widths, bike lane widths and freight truck turning movements. These are importance considerations in designing streets. Learn more at iamtraffic.org >>