Bellevue Adds to the 100-Mile Mountains to Sound Greenway Trail
Creating Connections: Addition to the Mountains to Sound Greenway Trail Will Improve Quality of Life for Bellevue Residents and Visitors
What makes a city livable? Quality transportation surely is part of it. Just as certainly are parks and recreational areas. The city of Bellevue, located in Washington State, is adding to a lengthy trail, known as the Mountains to Sound Greenway Trail and making their city more livable.
The Mountains to Sound Greenway Trail is a regional trail that runs over 100 miles. It starts in Seattle and ends in Ellensburg, Washington. Planners, who first envisioned the trail in 1990, had a goal of creating a way for a walker or bicyclist to travel on safe, enjoyable, non-motorized trails connecting Puget Sound urban areas, the Cascade Mountains, and Central Washington State.
Upon completion of construction of the 3.6 miles of trail in Bellevue, the trail will connect with two other segments so that it will go completely through the city. Bellevue sees it as an opportunity to improve the quality of life for residents and visitors alike.
Part of the 12-foot-wide multi-use trail will run parallel to Interstate 90. In addition to trail work, the project includes adding one lane of storage capacity on an off-ramp of I-90. Currently, the area around the off-ramp experiences lengthy back-ups as three lanes feed into one resulting in cars getting stopped along the highway and slowing down traffic that is continuing along the interstate.
“This adds one additional lane to the off-ramp, so there’s a place to store vehicles,” says Chris Masek, who works for the city of Bellevue Transportation Department and is serving as the Project Manager on the project. “We expect this to improve safety.” Masek emphasizes the widening is only for part of the off ramp.
As part of the first phase of the project, over half a mile of the trail will be added. When plans are further developed and funds become available, the trail will continue east and close the 3.6-mile gap. This phase of the construction includes a short flyover bridge (about a tenth of a mile) and a standard concrete girder bridge that, like the rest of the trail, will be 12 feet wide. Masek notes the bridge will provide safe and efficient travel for bicyclists and walkers bypassing the busy I-90 ramp/SE 36 Street/Factoria Boulevard Intersection.
Masek notes that due to high traffic volumes, no lane closures can be made on the off-ramp during daytime hours. To the south are businesses including the T-Mobile headquarters, and to the north is Woodridge residential area. Although work takes place 24 hours a day, the team faces restricted work hours for ramp closure so they need to be strategic in when they work. “All work on the west side of the project has to happen at night, which involves lane closures while work on the east side occurs during the day,” says Masek.
The high-traffic area also has a limited workspace. This has impacted the equipment used on the project. An 8-foot oscillator was used for shaft construction due to its lack of impact/vibration to the ground while operating adjacent to sensitive structures and existing utilities.
Schedule, Delivery and Financing
The design delivery model for this project was unique for Bellevue. They used a combination of city design personnel and outside consultants. “We usually do all in-house or consultants for design work rather than splitting it up,” says Masek. “However, we don’t have structural sources in-house needed for the structural design elements of the project.” The city team does not typically take on larger projects, like this one for in-house design.
Construction began in October 2019 and the project must be complete by the end of 2020. This tight deadline is due to a widening project planned by the state of Washington that includes a ramp that is adjacent to this project. Again, space is extremely constrained in the area so having two projects happening concurrently is not feasible.
The project is currently on schedule. Masek credits the team for staying ahead of issues that come up and making sure that they get resolved quickly so that they don’t impact the critical path of the project construction schedule.
Early in construction, the team ran into some issues related to identifying utilities, and this caused a slowdown. An example is a gas main that was not correctly located. In order to catch up, the contractor did some unique things such as drilling shafts on Sunday nights in order to accelerate part of the schedule.
Something that has helped keep the project moving was a thorough geotechnical investigation and well-designed plans. “Borings completed in design were deep enough to get a good representation of what we would find when work began,” says Masek.
Construction of the project is budgeted for $19.5 million. A majority of the tab is being picked up by the state ($14 million) while the city is picking up the remaining $5.5 million. “We’re on budget, and that’s a credit to the contractor and the city working together to quickly resolve issues and staying ahead issues as they come up.” says Masek.
The parts of the Mountains to Sound Greenway Trail that surround Bellevue are already well used so it’s no surprise that there’s lots of public support for the project. Masek says, “We did outreach early to get input from the community, and it was clear there was a desire of people in the area to fill in the gap.”
Soon, the first step toward filling the gap of the Mountains to Sound Greenway Trail will be completed. Residents and tourists will have more safe places for people to walk and bike. In addition, commuters will enjoy a safer, smoother ride and fewer backups. A number of the ingredients of a livable city are being met.