During a carefully choreographed series of activities, crews slid and lowered a new, permanent span for the Interstate 5 Skagit River Bridge into its final location and reopened the roadway to traffic on Sunday.

Now that the permanent bridge span is complete, a new phase of construction will soon begin. Drivers should expect additional nighttime detours of one or both directions of I-5 at the Skagit River Bridge beginning Monday, and continuing through mid-November. The detours will give contractor crews the space they need to begin retrofitting the overhead bridge supports.

A portion of the I-5 bridge collapsed into the Skagit River in Burlington on May 23, after a semi-truck struck critical steel supports. This section of I-5 carries 71,000 vehicles each day. The I-5 Skagit River Bridge reopened to traffic on June 19, after contractor crews installed temporary spans.

Starting Saturday evening crews used a complex system of hydraulic jacks, Teflon pads and long steel rails to lift and move the two sections of the temporary span onto a work platform for disassembly. Then they used a similar set-up to usher the new, 900-ton concrete span into place.

.Although crews encountered some complications along the way, including the time-consuming process of cutting through thick metal plates before being able to lift the temporary span, they still finished building and relocating the bridge more than two weeks before the Oct. 1 deadline. It took 19 hours to swap bridge sections.