WEST LEBANON — Work to rebuild the two bridges carrying Interstate 89 over the Connecticut River started this week, but, transportation officials say, drivers won’t see a major change in their commute for at least a year.
Crews with Bow, N.H.-based R.S. Audley began site work on the $43.8 million project on Tuesday. Their first task is to build a new pier and deck that will serve as temporary travel lanes.
“It is a five-year project and we will spend the first year and a half coming up out of the river because we need to construct new piers between the two existing ones,” Jeffrey Potter, an engineer with the New Hampshire Department of Transportation, said Wednesday.
Aside from cranes working alongside the river, drivers may not notice the crews until 2021, he said.
Once work on the new travel lanes is complete, southbound traffic will be diverted onto them as workers remove the current bridge’s deck and superstructure. They’ll then widen the highway to create auxiliary lanes that will allow traffic to move more freely between interstates 89 and 91.
Once the southbound bridge is complete, construction will then focus on the northbound bridge, with traffic headed into Vermont diverted onto the temporary roadway.
The DOT also proposes closing the northbound lane overnight for up to a month sometime in 2022 so that crews can transport large pieces of steel, Potter said.
A detour in those overnight hours — which was reviewed last year by the Hartford Selectboard and Lebanon City Council — would force northbound motorists to get off at Exit 20 in West Lebanon, drive north on Route 12A, then over the Route 4 bridge to White River Junction and have them travel south onto I-91 before exiting back onto I-89.
State officials also say they may later close the ramp that ferries northbound traffic off I-91 onto I-89 south toward New Hampshire for a few days, which would require a local detour through White River Junction and West Lebanon.
“We’re just getting started and you’re probably not going to see a whole lot going on for the next year,” Potter said. “While it will still be an active construction site, it shouldn’t impose real impacts to the traveling public.”
The 840-foot “sister bridges,” which were constructed in 1966, carry about 41,000 vehicles a day and are showing “severe signs of distress,” according to a 2017 grant application the New Hampshire DOT submitted for the project.
“The concrete bridge decks exhibit signs of distress, including cracking, delamination, and efflorescence at various locations,” said a separate 2014 report. “The lead-based girder paint system is failing as evidenced by cracking, flaking, and peeling, and light rust has formed in many locations on the steel members.”
Both structures are on New Hampshire’s “red list” priority ranking, meaning they’re inspected twice yearly due to their poor condition. Other state-owned bridges receive inspections every two years.
Tim Camerato can be reached at tcamerato@vnews.com or 603-727-3223.