The proposed new Interstate 5 bridge could lead to a 13% to 17% reduction in crashes by 2045, according to projections.
On Friday, Sept. 20, the Interstate Bridge Replacement (IBR) Program released its 10,000-page draft Supplemental Environmental Impact Statement (SEIS). The draft, a National Environmental Policy Act requirement, evaluates locally preferred bridge alternatives, comparing them with a “no-build” option and assessing their potential environmental, traffic and safety improvements.
During the press conference, IBR Program Administrator Greg Johnson outlined the main goals of the new bridge — reducing accidents, easing traffic congestion for both people and freight and enhancing public transportation. The plans include expanded pedestrian and bike paths and light rail. Additionally, the design will address the over a century-old bridge’s earthquake vulnerability, significantly improving the structural stability of the new bridge.
Johnson highlighted the significance of the draft’s release during the press conference.
“I was telling our team that mega projects are filled with moments of frustration and very few moments of joy. This is one of those moments of joy when we hit a significant milestone. so the release of the draft supplemental document is a very key milestone … for not only this project but for the community,” Johnson said during the press conference.
Proposed bridge design options
The SEIS outlines various design alternatives aimed at reducing congestion. The final bridge design could include combinations of the following options:
• Two ramp options connecting the bridge to C Street in Vancouver are under consideration. The new design may include one ramp, both or neither.
• Five potential locations for a Vancouver ride-and-share station are included, with three near the waterfront and two south of the Mill Plain interchange by I-5.
• A potential realignment of I-5 in downtown Vancouver could shift the highway to the center or to the west.
• Three bridge span alternatives are considered to accommodate boat traffic: a double-deck fixed-span bridge with light rail and pedestrian crossings below, a single-level fixed-span bridge with all traffic on the same level, or a single-level moveable span. The movable 292-foot-wide section would be raised for boats, causing some traffic delays.
The design also proposes one or two auxiliary lanes to ease merging traffic, along with wider lanes — up from 10.5 feet to 12 feet. IBR assistant program manager Frank Green explained that the current narrow lanes and lack of auxiliary lanes, coupled with closely spaced interchanges near the bridge, have contributed to both congestion and crashes.
“As you look at [its] existing conditions, we see significant amounts of accidents and crashes are caused by the geometry and the configuration of those seven closely spaced interchanges, as well as the bridge itself knowing [there’re] narrow lanes for the freeway and no shoulders,” Green said.
Crash and traffic projections
Within the IBR study area, which includes the bridge and ramp intersections in both downtown Vancouver and Portland, 1,780 crashes took place between 2015 and 2019, according to a previous study. This figure includes seven fatal crashes and 17 accidents resulting in serious injuries.
Without a new bridge, IBR expects crashes to increase by 28% from 2019 levels by 2045. A bridge design with one auxiliary lane could reduce crashes by 13%, while two auxiliary lanes are expected to reduce today’s average crash reports by 17%.
Congestion -— speeds below 45 mph — is also projected to increase significantly. By 2045, without a new bridge, northbound traffic could face 14 hours of congestion on an average weekday, while southbound traffic could see 16 hours. A new bridge is projected to reduce those times to nine hours northbound and 4 3/4 hours southbound. With two auxiliary lanes, congestion could drop further to six hours northbound and 4 1/2 hours southbound.
In 2019, the current bridge experienced an average of 143,000 weekday trips. IBR predicts this will rise to 180,000 by 2045 without a new bridge. With a new bridge, the traffic volume would drop slightly to 175,000 weekday trips, thanks in part to public transportation improvements.
Community feedback and public hearings
The full 10,000-page SEIS is available online at interstate bridge.org/DraftSEIS#review. Public feedback will be accepted on the website until Monday, Nov. 18.
IBR will hold two in-person public hearings in October:
• 5:30 p.m. to 8:30 p.m. on Tuesday, Oct. 15, at Gaiser Hall, Room 150, Clark College, Vancouver
• 5:30 p.m. to 8:30 p.m. on Thursday, Oct. 17, at the Portland Expo Center
An online public briefing on the draft will be held via Zoom from 5:30 p.m. to 7 p.m. on Wednesday, Oct. 9. Two virtual public hearings will also take place in October: one from noon to 2:30 p.m. on Saturday, Oct. 26, and another from 6 p.m. to 8:30 p.m. on Wednesday, Oct. 30. All online meetings can be accessed at interstatebridge.org/calendar.
