In place, paved and striped in 60 hours

In one weekend, MaineDOT replaced a 60-year-old structurally deficient bridge, carrying I-295 over Veranda Street in Portland, Maine. Work began to remove the existing structure on Friday, April 22, at 7 p.m., and by Monday, April 25, at 7 a.m., the bridge was in place, paved, striped and open to traffic.

We instituted several best practices to support MaineDOT’s commitment to deliver projects safely under strong fiscal stewardship and with minimal disruption.

Evaluate impact vs. cost.When executed correctly, ABC can be well received by the public, as it was with this project. But ABC is not always the best approach. The appropriateness of it depends heavily on the benefits realized by the traveling public and the cost of its application.

Had we elected to use conventional construction methods, approximately 53,000 motorists would have been subjected to years of daily congestion. With accelerated bridge construction, we dramatically compressed the traditional timeline. Because of its expedient nature, ABC requires considerably more resources than conventional construction, but those costs were offset by eliminating the construction of a substantial temporary bridge and by significantly minimizing travel delays end users would have otherwise experienced.

Great partners make a project go smoothly. A project of significant scale and complexity presents significant challenges and risk without the additional burden and learning curve of teaming with a new, unfamiliar designer or contractor. We’ve found that a proven risk mitigation strategy is contracting with partners who have significant ABC experience and a history of delivering success for our department.

The construction method should inform the design. When designing for ABC, the project team should focus on eliminating unnecessary complexity and designing for simplicity. Recognizing this, the Veranda Street Bridge project called for replacing the existing three-span bridge with a shorter and simpler jointless, single-span structure. The area beneath the remainder of the existing bridge was converted into embankments prior to the roadway closure. This simplified design saved precious time during the roadway closure and will reduce long-term maintenance costs.

Early engagement of the construction community can reduce risk and increase competition. After we advertised the bridge replacement project, we received contractor feedback regarding the contract language and concerns regarding the risks they perceived in this first-of-its-kind project for MaineDOT. Bidders asked for contract language that was less restrictive and would provide them more flexibility in how they progressed the work during the roadway closure. Based on this input, and given that project success was critical, MaineDOT decided to reissue the bid documents. Before doing so, MaineDOT sent a letter asking local contractors to help modify the contract language through a series of group and confidential 1-on-1 meetings between MaineDOT, HNTB and the contractor. In exchange for their time and insights, participants would be the only ones prequalified to bid on the project. Three contractors accepted the invitation. We met with them as a group and then individually, allowing each firm to share concerns, concepts and approaches they might not want competitors to hear.

After the intake sessions, we updated the contract documents to allow for the contractors’ ideas and recommendations where appropriate without disclosing any one firm’s idea. The revisions were reviewed with contractors and subsequent iterations were developed to arrive at terms that balanced the needs of MaineDOT and the contractors.  For example, we learned some contractors preferred the flexibility of being able to choose how the bridge was moved into place, either through sliding the bridge laterally, lifting it into place, or rolling it into place. The specifications were subsequently revised to provide performance requirements that allowed for this flexibility. Through these adjustments, the winning contractor proposed the use of self-propelled modular transporters.

A protected work zone is the safest option. The project called for building the upper portion of the new bridge on temporary supports. These supports were able to be built away from the existing highway after coordination with the contractor. At the same time, the new bridge foundations were constructed beneath the existing bridge safely separated from traffic. The new bridge was then lifted and “driven” into place using a SPMT. Because safety is of the utmost importance to MaineDOT, we chose to fully close I-295 and Veranda Street while the existing bridge was demolished, and the new bridge moved into place. Ultimately, creating the preparatory work out of traffic, and moving the structure into place with closures created a much safer work zone.

Virtual public outreach enabled the successful closure. MaineDOT strives to openly communicate with everyone involved in or affected by our infrastructure projects. We had many in-person meetings and workshops with constituents about the bridge replacement project before the pandemic. During the pandemic, when the project went out to bid and then into construction, we relied upon virtual public involvement to maintain our pledge of transparency and open communication. Ultimately, we found virtual public involvement to be more effective, efficient and far reaching than communicating through traditional channels. In fact, we’re convinced our virtual communication efforts made full closure of the interstate, and our aggressive campaign to influence motorist behavior during the closure, possible.

Leading up to this project, our virtual public involvement process consisted of pre-recorded presentations played on-demand with public comments collected and responded to as they were received. For this project, we implemented MaineDOT’s first virtual podium meeting. Through this process we provided a live presentation online. Following the live presentation, the meeting attendees were invited to type questions or comments in a chat box that were then answered in real time by project team members. The benefits offered by this process were significant:

• • We were able to engage a larger, broader audience
  • We could correct misconceptions instantly
  • We saved hours of project time and resources associated with conducting a live meeting
  • We engaged in more meaningful dialogue
  • Meeting was recorded and made available on-demand for those who could not attend the live meeting

The success we experienced with virtual public involvement on the I-295 bridge replacement reaffirms MaineDOT’s intentions to move forward with virtual public engagement as a standard practice in the future.

Successful projects build support for future work. The Veranda Street project resulted in a new, lower maintenance bridge delivered in record time and with broad public support. The successful delivery of this project allowed MaineDOT to build public trust, a critical measure for any public agency.