A ‘new-to-Boulder’ bike facility for low-stress left turns

As part of the city’s Pavement Management Program Mobility Enhancement Initiative, 17th Street has recently received an upgrade. The initiative improves walking and bicycling conditions by strategically pairing the installation of signing, striping and markings of streets with annual street resurfacing.

Based on national best practices, upgrades to 17th Street include a “two-stage left-turn queue box” to provide low-stress bicycling conditions.

The new addition to Boulder helps people on bikes make left turns without having to leave the bike lane and enter the vehicle travel lane at signalized intersections.

How it works

The queue box is located outside of the flow of traffic between the curb and vehicle travel lane. Its bright green design visually notifies cyclists and drivers of a designated area where bicyclists can choose to wait to make a left turn in two stages.

After a bicyclist enters the queue box and positions themselves in the direction to cross the street, they may cycle across the intersection when the traffic signal turns green or when the coast is clear.

People bicycling can choose to use the queue box or continue to turn left from the vehicle travel lane. There is no requirement to use the queue box.

There is a “no right turn on red” restriction for drivers.

Why do we need it?

The queue box is designed to reduce challenges and improve comfort for people on bikes.

For example, it can be difficult for children and adults on separate bikes to make a left turn together. The queue box provides enough room for multiple bicyclists, such as parents cycling with children, and common types of bikes, like cargo bikes and bikes with trailers.

Why here?

These improvements to 17th and Walnut streets introduce a low-stress option that helps connect adjacent bike lane facilities for community members in the area.

Both streets were prioritized as part of the city’s Low-Stress Walk and Bike Network Plan, a roadmap of corridors slated for improvements to decrease the level of traffic stress for people walking and bicycling across Boulder.

17th Street improvements include:

• Resurfacing of 17th Street from Pearl Street to Macky Drive

• Two-stage left-turn queue boxes for making left turns onto Walnut Street from 17th Street, including “no right turn on red” signs for drivers

• Green pavement markings to increase the visibility of bike paths on Canyon Boulevard and Arapahoe Avenue

• A new bike lane segment southbound from Pearl Street to Walnut Street

• Newly restriped bike lanes and crosswalks between Pearl Street and Macky Drive