Interstate Bridge Replacement Program Recommends 8-Lane Crossing | News


PORTLAND, Oregon – Interstate Bridge Replacement (IBR) unveiled the latest of its recommendations for the configuration of the proposed new bridge Thursday. The most notable choice was the recommendation of a single set of auxiliary channelsfor an overall width of eight traffic lanes.

This is a reduction from the ten-way design that was chosen for the program’s predecessor, the failure Columbia River Crossing (CRC) project; the three existing traffic lanes plus two auxiliary lanes on each side.

Community opinion polls conducted by the IBR program revealed that 85% of respondents favored one set of auxiliary pathways and 74% favored two sets. Clark County residents were more likely to prefer two sets over one, while Oregon residents were more evenly split.

“We’ve taken a lot of feedback, looked at the overall impacts and focused on climate and equity, and are landing on the only ancillary track,” program manager John Willis said during a briefing. Thursday morning meeting of the project’s executive steering group.

The eight-lane design is paired with a reduced interchange at Hayden Island. The CRC plan would have maintained the island’s current full interchange, which allows traffic to enter and exit the freeway in both directions.

The IBR recommendation calls for maintaining only one southbound exit ramp and one northbound entrance ramp. Drivers traveling between Portland and the island would instead use the Marine Drive interchange on the Oregon mainland and cross over a separate arterial bridge.

That recommendation was based on a desire to minimize the highway’s impact on Hayden Island residents, Willis said, coupled with community surveys indicating that Washington residents travel to Hayden Island more often than residents of Washington. ‘Oregon.

Most of the other high-level configuration recommendations were already known. The project team revealed last month that they would recommend including light rail on the bridge, rather than bus rapid transit, although Willis’ presentation raised the possibility of a bus on the bridge. shoulder on the new bridge, which C-Tran already uses on Interstate 5 south as you approach the bridge.

In another downsizing from the CRC plan, the team recommended that the light rail line remain adjacent to I-5 in Vancouver and end near Evergreen Boulevard, rather than branch off into streets in the downtown of the city and terminating at Clark College.

Light rail was one of the most controversial parts of CRC, especially in Washington, but Willis said IBR opinion polls found strong support for light rail among residents on both sides of the border. river: 90% in Portland, 69% in Vancouver and 57% in Clark County excluding Vancouver.

There’s one place where the IBR project is gaining momentum: the team is recommending a complete replacement of the North Portland Harbor Bridge, which carries I-5 from mainland Oregon to Hayden Island. CRC’s plan called for upgrading and maintenance of the existing bridge.

The IBR team also recommended that the project include a variable rate toll, which the CRC is also said to have introduced, although it is too early to know what the toll amounts would be.

One detail that still remains unresolved is the configuration of the bridge itself. The team previously outlined two options: twin bridges that would each carry one direction of the highway, or a single bridge that would stack the highway on two bridges. The team is still evaluating those two options, program administrator Greg Johnson said, but there’s still time to make a decision later.

Together, the various design recommendations form the Locally Preferred Alternative (LPA), which is the single conceptual design that the project team will submit to the federal environmental review process.

The LPA isn’t a complete engineering design — in fact, it’s just a 2% design, Willis said. Assuming the PLA receives federal approval, detailed design work is expected to take place over the next few years, with construction expected to begin in 2025.

In the shorter term, the project team will seek local approval of the APL’s choices. Thursday’s presentation came at a meeting of the project’s executive steering group, which includes representatives from local governments like the City of Portland and transit agencies like TriMet.

These representatives will now be responsible for bringing the PLA back to their respective boards and councils for consideration. The IBR team is also Friday morning meeting present the APL to the bi-state legislative committee that oversees the program.


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