S 277th Bridge No. 3126 Replacement Project
Project completed in Fall 2021
King County completed major construction on the 277th Street Bridge Replacement Project on Friday, November 19, 2021. All lanes of traffic are now open.
Overview
This project replaced the S 277th Street Bridge over Mullen Slough with a concrete box culvert. The 16-foot-long bridge was located on a four-lane road that connects Interstate 5 to State Route 167 in Kent and Federal Way. Because the 70-year-old bridge was load-restricted, it was unable to support large trucks. This made it difficult for some fire engines, garbage trucks, dump trucks, and concrete mixers to do work in the area. In 2021, our data showed that this location had a traffic volume of about 23,000 vehicles per day. 2,600 of those vehicles were trucks carrying an estimated 4 to 10 million tons of freight per year. This road is a designated county snow/ice route, lifeline route, and Green River Valley flood evacuation route. This work was necessary to meet the demand of cars, trucks, and service vehicles that use the road.
The new replacement culvert provides unrestricted access for all vehicles. It also gives support to the environment by improving fish passage and removing creosote timber pilings from Mullen Slough.
Photos
The second half of the new concrete box replacement culvert is installed on Sept. 16, 2021.
The second half of the new concrete box replacement culvert, in place on Sept. 16, 2021.
The first half of the new concrete box replacement culvert is installed on Sept. 1, 2021. Next, crews will bury this half, rebuild the road on top of it, and move both lanes of traffic over so that we can start work on the second half of this project.
The first section of the new culvert is lowered into place on September 1, 2021.
August 11, 2021 - Steel plates are used to cover the area under S 277th Street that has been excavated. The plates also cover a de-watering system that diverts Mullen Slough away from the construction zone.