Public input sought on project, which could impact traffic on highway
State and federal officials are evaluating solutions for repairing or replacing six historic bridges between Huelo and Hana town to maintain a “safe and functional roadway.”
The bridges, which are identified by the state Department of Transportation as high priority for improvements, include Kailua Stream Bridge at Mile Post 5.9, Makanali Stream Bridge at Mile Post 8.2, Puohokamoa Stream Bridge at Mile Post 11, Kopiliula Stream Bridge at Mile Post 21.7, Ulaino Stream Bridge at Mile Post 27.9 and Mokulehua Stream Bridge at Mile Post 28.3.
“The team has been working very hard,” Tammy Heffron, consultant project manager from HDR Engineering, said during the presentation. “It’s definitely not an easy project or an easy site, but we’re working on getting this thing going.”
Work on the project is currently in the environmental compliance and design process with construction slated to begin in the spring of 2023; it will take one year to complete each bridge, with possibly two undergoing work at the same time, Heffron said.
DOT spokesperson Shelly Kunishige said Wednesday that the anticipated costs at this time are around $40 million, but “as we improve the project with input from the community, and additional technical information from our design team, we will be able to further refine costs.”
During the virtual meeting, the project team discussed the proposed bridge solutions and considerations for how they plan to improve the aging bridges and maintain traffic flow.
Environmental specialist Sandy Beazley said that these bridges have “unique engineering and construction” on a highly intact belt road system, which is “really no surprise because these bridges were built between 1908 and 1947.”
They have significant features that contribute to the historic district of East Maui, Beazley said, like the abutments (bridge supports), the rock walls and railings.
The purpose of the project is to address, improve and repair the existing structural conditions of the six bridges in a “sensitive manner,” so they remain functional, reliable for transportation and safe under load capacities, Beazley said.
The current load capacity does not allow for full fuel or water trucks or large maintenance trucks. The bridges also don’t meet current sidewalk standards and the railings don’t meet existing crash-safety standards.
“As you know, the Hana Highway is kind of the life blood of East Maui communities in terms of providing transportation for both local and regional travel — taking kids to school, going to stores, employment centers, as well as an economic driver, for better or for worse, tourism as well,” he said.
Throughout the course of the project, including on Tuesday night, the community asked for minimal impacts to traffic during construction, a quicker construction schedule overall and that officials retain the historic character of bridges, including keeping them single-laned and adorned with the bouldered railings, if possible.
“We want as long lasting solutions as possible because otherwise you’ll see us out there every year working on a bridge, which I know some of us in the community (do) not want,” Beazley said.
Two solutions were considered for the bridges — rehabilitation, which would involve maintaining as many existing character-defining features “as practicable” while making design improvements to meet project goals; or replacement, which involves maintaining as many existing character features, but replacing a bridge when needed and matching existing character features as best as possible while still achieving design concepts to meet project goals.
Heffron said that the team evaluated the replacement alternative, noting that it would be a shorter construction schedule with less traffic impacts, lower costs, lower risks of impacting streams and longer design life. Existing substructure elements would also be retained, she said.
For example, proposed bridge renderings for Kailua, Ulaino and Puohokamoa Stream Bridges would include single-span concrete girders stretching over existing supports.
A single-span concrete girders slab is proposed for Makanali Stream Bridge and just a single-span concrete slab over existing supports is proposed for Mokulehua, which is the oldest structural bridge on the project, dating back to 1908.
Kopiliula Stream Bridge is the “most challenging” structurally due to the East Maui Irrigation channel feature, narrow design and historic landmark, lead structural engineer Sean Oroho said.
The team is proposing a new two-span, concrete bridge adjacent to the existing bridge.
A method called “bridge slide construction” is being proposed to complete the entire project, as opposed to installing a temporary bypass bridge, Oroho said.
Slide construction is a “proven off-line construction method” that is safer, yields lower costs and is a lower risk to adjacent property owners and allows better access to their homes, he said.
However, this method requires overnight closures and multiday full closures.
To begin construction, temporary supports for the new bridge would be built to the side of the existing bridge, which would remain open to traffic using temporary traffic signals.
Then, new bridge supports would be built behind existing bridge supports. The existing bridge remains open to traffic with limited nighttime closures during “off peak hours,” Oroho said.
The next step involves removing the existing bridge, but preserving the existing bridge support system. At this time, the roadway and bridge are temporarily closed to traffic, “but I just want to stress that this is done as quickly as possible,” he added.
The new bridge would then be slid into place.
Specific details regarding emergency services and access will be presented at the next public meeting. This week’s meetings are the third in a series of four which began in January 2020. More will be held in 2022.
All proposals are conceptual and are open for public input as the departments finalize the design, Heffron said.
For more information on the Hana Highway Bridge Improvements Project, visit www.hanabridgeimprovements.com. For a copy of the full presentation, visit hidot.hawaii.gov/presentations/.
Those unable to attend the meetings can provide input through the project website or by contacting the project manager, Tom Kubicz, via email at email@example.com, or by phone at (720) 963-3498 and (202) 981-4183.
* Dakota Grossman can be reached at firstname.lastname@example.org.