Flanders Crossing: Connecting Northwest PDX
When built, pedestrians will cross I-405 safely downtown
Flanders Crossing, the proposed pedestrian bridge over I-405 downtown, will connect foot and bike traffic between the Pearl District and the Northwest District and eventually tie into long-term plan for the city's proposed Green Loop.
After successfully being funded in August, construction on the new pedestrian crossing over I-405 could begin as soon as April 2018.
The proposal for Flanders Crossing is located between Northwest 15th and 16th Avenues. A new traffic signal is proposed at 16th and Flanders, but not at 15th due to traffic studies of the I-405 southbound off-ramp.
The Portland Bureau of Transportation is providing $3 million and ConnectOregon is granting $2,877,000 to reach a total cost of $5.9 million. ConnectOregons contracting staff is in the process of developing intergovernmental agreements with all the successful recipients of its grants, after which a contractor will be chosen for the build.
Scott Turnoy, freight program manager with ODOT, is involved with connecting the transportation project with the grants.
Theyre expecting construction perhaps by early 2018, so theres a lot of prep work scoping, permits to acquire final plans for engineering that has to happen first, Turnoy said. Long-term, its a critical connection for that segment from upper Northwest into Old Town along Flanders as a bikeway for the greenway.
PBOT analyzed the bridges feasibility in a study that looked at six options for how to design and develop the bridge.
They went through this pretty extensive assessment and did come up with preferred alternatives, but its hard to say what itll finally end up looking like, Turnoy said. I know in the study and plans theyve got a lot of information that the region folks and Bicycle Advisory and Pedestrian Advisory Committees reviewed and saw this is an important project, an important connection to be made.
The PBOT feasibility and alternatives study was conducted in November 2015, to provide safer pedestrian and bike crossing between the Northwest District and Pearl District. The study lists site constraints including traffic impacts during construction and the partial demolition of an existing ODOT retaining wall.
Pedestrian and bicyclist active communters, residents and shoppers safety is the reason there is a need for Flanders Crossing.
My sense is that its a safety issue, a mobility issue of getting folks onto a safer crossing and off of some of the busier auto and truck thoroughfares in Northwest, and also to connect the bikeway along Flanders Street, Turnoy said. Given this one is a bike and pedestrian crossing over an interstate, there are certainly implications there for what the project needs to implement for safety.
As it is, Glisan and Everett Streets (north and south of Flanders Street) do pass over I-405 with concrete bridges, but each offers only one sidewalk lane that arent connected to safely marked crosswalks at the ends.
PBOT aims to make Portlands transportation system the safest possible, and to move toward zero traffic-related deaths, the study reads. The Flanders Crossing bridge should be designed to incorporate crosswalk strategies and alignments to protect the most vulnerable transportation users.
The alternative design costs range from $4.05 million to $8.12 million, with the prefered design a 24 foot wide single span custom steel bridge estimated to cost $6,009,656. It would have two six-foot wide sidewalks and two six-foot bike lanes in the center. The cost estimates account for preliminary engineering, construction, project management and construction engineering.
Other options include a Tilikum Crossing-like cable-stayed bridge, or two 14-foot wide single span parallel truss bridges. One of the options offers a plaza in the center, similar to park blocks in Denver that overpass the I-70 there.
As for seismic resiliency, the physical condition and status of bridges in the Portland area following an earthquake becomes a paramount factor in determining routes for emergency services, government operations and the safe mobility of the general public, the study said. This recognition rings especially true for the Pearl District, bounded by the I-405 freeway the bridges and overpasses that support or span I-405 were built prior to current seismic design standards.
In case of a seismic event, the pedestrian bridge could be used by vehicles. The favored custom steel bridge would accommodate active pedestrians and cyclists sharing sidewalks and vehicles on the 12 foot center lane.
Generally, I think any construction project ODOT is looking to fund is trying to take that (seismic) aspect of the project into account have statewide seismic lifeline studies, certain corridors and facilities along the state (transportation) system and prioritize for upgrades seismically, Turnoy said.
Based on the application submitted over a year ago, the project is expected to be complete by spring or summer of 2019.