The outside northbound lane of the 4th Avenue South bridge that many might know best as “south of Costco” could remain closed another year. That’s what we found out when we inquired with SDOT as promised. The status of the lane – already closed for more than a year – came up in comment discussion following our recent update on another 4th Avenue S.-related topic, the since-removed temporary bus lane. Here’s how SDOT spokesperson Ethan Bergerson responded to our inquiry about the 4th Ave. section some call the “Argo bridge.” He says the lane was closed “so that the bridge remains safe to travel on,” continuing:

We are still in the process of assessing what work is needed to repair the bridge and ensure public safety.

Since the 1985 rechannelization to 4 lanes, we have seen increased traffic and loads (17,000 daily users in both directions) as well as a deterioration of the cantilevered ends of the span piers. While these restrictions ensure the bridge remains safe to travel on, the outer edges of the bridge cannot continue to support the loads it was carrying. In late 2017, we decided to close the northbound curb lane and restrict large trucks from using the southbound curb lane to protect the structural integrity of the bridge and ensure that it remains safe to drive on.

This project has been complicated by the fact that Union Pacific Railroad owns the right-of-way under the bridge and the permit we received from Union Pacific Railroad requires that we do not work in the Argo rail yard. Working on top of the bridge makes the repairs more complex. As a result we brought a consultant onboard to help determine what needs to be done to make repairs so that we can finalize the design.

Once we get started, the repairs should take anywhere from 6 to 9 months to complete and we hope to have the northbound curb lane reopened by the end of this year or early 2020.