What you need to know:
- The southbound span of the Knik River bridge on the Glenn Highway will fully reopen Wednesday, ending more than two months of major detours. The northbound span reopened just before Memorial Day.
- Although major resurfacing is complete, final pavement and joint work will continue through late July, with some single-lane closures scheduled outside peak hours.
- Despite initial concerns, traffic flow remained mostly smooth during the work, aided by the use of a Road Zipper machine, officials said. The project will wrap up later this summer, with similar work planned for the Peters Creek bridge next year.
PALMER – The southbound span of the Knik River bridge on the Glenn Highway will fully reopen Wednesday, shifting traffic back to regular lanes and ending more than two months of detours, even as final paving work remains.
The change is scheduled to coincide with the July Fourth holiday weekend, state transportation officials said. The northbound span reopened just before Memorial Day weekend after nearly a monthlong closure.
With both sides fully open, traffic will no longer detour to share three lanes, officials said. No additional full-span closures are expected.
While the deep resurfacing work that prompted the closures is complete, crews still need to lay new pavement over the finished bridge 1,532-foot bridge decks, officials said, a step that will carry periodic single-lane closures over the coming month.
Drivers will also likely notice a bump at either end of each span where the bridge joints meet the highway. Crews are scheduled to fix those sections with a smooth concrete-polyester overlay in late July, said Jason Lamoreaux, a construction manager with the Alaska Department of Transportation and Public Facilities who is overseeing the project.
That step could not be completed before the reopenings because the material used on the decks requires about 30 days to cure before the overlay can adhere, he said. Rather than close the spans completely for that work, crews will shut down single lanes outside of peak commuting hours, he said.
The project will fully wrap late this summer after crews remove the crossover lanes used to divert traffic from one span to the other during the closures, officials said. Work will then shift south to Peters Creek in preparation for similar work that will temporarily close part of that bridge next summer, Lamoreaux said.
While state transportation officials initially feared the Knik project would trigger major delays and suggested commuters telework or carpool, overall traffic flow during the project was instead much better than expected, Lamoreaux said.
He credits that success to the use of a Road Zipper barrier-moving machine, which allowed crews to quickly reconfigure lane barriers twice daily instead of relying on workers to manually move cones, he said.
“The zipper barrier actually accommodated the traffic a lot better than we expected,” he said.
The machine, which contractor Hamilton Construction rented and shipped into the state for the $20 million project, will likely be used for future state work that carries significant traffic impacts, he said.
About 31,000 drivers travel across the Knik River bridges daily, according to state traffic data. The recent overhauls are the first of their kind for the decades-old spans, officials said. The southbound bridge was built in 1990; the northbound bridge was originally constructed in 1965.
- Contact Amy Bushatz at contact@matsusentinel.com
