Many can relate to the anxiety a driver feels attempting to turn right onto a busy, fast-moving road from a connecting side street. This challenge is heightened when cutting across several lanes of traffic to turn left. Finding that often rare, split-second opening of safety between cars to dive into used to be a stressful undertaking often required of commuters regularly utilizing State Route (SR) 305 where it intersects with West Port Madison and Adas Will Lane. To remedy this issue, WSDOT decided to install two roundabouts at the problematic intersections to help with this issue, enlisting a project team with Osborn Consulting as a key team member for drainage.
The team’s main goal was to improve traffic flow and mitigate the potential for collisions along the heavily used SR 305. This was achieved through coordination with WSDOT as well as the City of Poulsbo, the City of Bainbridge Island, Kitsap County, Suquamish Tribe, and Kitsap Transit. It was no easy feat – the complex nature of the sites raised several design challenges that required frequent collaboration and creative solutions to overcome.
Some site constraints revealed themselves in the form of a city park with trees that could be impacted and required easements, steep slopes influencing how stormwater was conveyed, and even a historic cemetery that needed to be avoided. Each constraint required careful consideration to find a practical solution that also optimized the use of the available space. With multiple jurisdictions following different codes all within the same area on top of the sites’ existing conditions, this project ended up being an excellent exercise in problem solving. Despite the hurdles, Osborn’s engineers were able to develop high quality, actionable designs that addressed relevant limitations and resulted in two roundabouts offering a variety of improvements.
It’s not often that Osborn team members get to directly enjoy the fruits of their own labor, but in the case of one of our engineers, this project hit close to home. One of our engineers who worked on the project routinely commutes to the Seattle office using SR 305 and was quite familiar with the challenging nature of that particular stretch of road. Wait times to turn were long, and the lines of idling cars producing pollution during rush hour proved to be environmental hazards. However, after construction was completed in November 2024, the upgrades became immediately apparent. The new roundabouts slow down through traffic in addition to allowing drivers to merge more seamlessly, regardless of which direction they are heading. The improvements also provide pedestrians with a safer way to cross SR 305, something our team member greatly appreciates when going on runs around her neighborhood. With new dedicated multi-use paths, updated sidewalks, pedestrian refuge islands, and enhanced access to bus stops, the area has become significantly safer and more walkable.
Osborn is honored to have worked with such an involved and passionate team on this important project. Being able to contribute our expertise and positively impact local communities is all we can hope for, and benefiting from our own efforts is certainly a bonus.
