SDOT will create temporary bike lanes to fill a gap in the Duwamish Trail and to improve safety on a significant stretch of 1st Avenue S in SoDo while crews work to repair the Spokane Street Bridge to West Seattle. Work will begin Wednesday.

As we wrote in a post last week, “Creating two miles of new bike lane is not a small feat, but these are the moments where SDOT and the city’s elected leaders can rise to the challenge and show the people they can do great things.” If the city nails the design here and creates a safe, connected and comfortable bike lane on a wide industrial street, it would be a triumph. I can’t think of another temporary bike route project of this scale in Seattle, especially one built in such a short timeline. The department will be observing the temporary lane to learn how to do it better during future closures, according to the post on the SDOT Blog: “Creating this temporary bike lane detour will help us to be more agile and able to consider similar detours during planned low bridge closures and at other locations.”

The Duwamish Trail connection on W Marginal Way just south of the Spokane Street Bridge has been in the works for years and has already gone through extensive public outreach.

The SDOT Blog post does not include a diagram of the planned bike lanes on 1st Avenue S, but there is a description that includes 1,700 traffic cones. I created an estimated graphic of what the street might look like once the lanes are in place:

This lane represents a serious sense of urgency within SDOT to address a bike safety problem, and it is probably the single biggest project to date entirely overseen by Mayor Bruce Harrell’s new SDOT Director Greg Spotts. The details will be important to make these traffic cone bike lanes work, including the details of how intersections function and whether the cones get knocked over and moved. So stay tuned, because Seattle Bike Blog will definitely be out riding these lanes as soon as they are ready.

More details from the SDOT Blog:

We have been sequentially and intentionally working to enhance the bike route over the past week. Our first step after the bridge closure was to clear windstorm debris, manufacture and install detour route signs, and review the asphalt condition to see if spot improvements were needed.

This week, we are converting sections of W Marginal Way SW and 1st Ave S curb lanes to temporary protected bike lanes using cones, barrels, paint, and signs. The temporary bike lanes will remain until the Spokane St Swing Bridge reopens. We continue to procure traffic control devices and finalize the traffic control plan. We plan to begin installing the bike lanes on Wednesday, Jan. 4.

What to expect

No Parking signs were placed on Friday, alerting businesses to expect a change. Since then, we have worked to secure the equipment to install the detour, including 1,700 traffic cones, and manufacturing additional signs. Starting Wednesday, you will see us working in the curb lanes.

While the temporary bike lanes are in place, 1st Ave S will have one general-purpose traffic lane in each direction, a center turn lane, and one bike lane in each direction. As possible, existing on-street parking will remain but be restricted near driveways to help people biking and driving more easily see each other. In two instances at the north and south ends, people on bikes will have to use the sidewalk—see map above. You may wish to get off your bike and walk it through these areas with pedestrians.

We will also convert the southbound general-purpose travel lane at the northern segment of West Marginal Way SW to a temporary protected bike lane. We expect this to have a minimal impact on people driving, as this is not a through-lane.

We will check the detour twice daily to reset cones, barrels, or signs that may have shifted while the temporary bike lanes are in operation.