What you need to know:

• A new state study will examine whether to build a tunnel under the Knik Arm to create a second connection between the Mat-Su region and Anchorage.
• The study, estimated to cost at least $1 million, will be completed by late next year. It will evaluate construction costs, engineering methods, environmental impacts and other factors.
• The study is the latest in a series of similar proposals commissioned by the Alaska Department of Transportation over the past 20 years. It was prompted by recent advances in tunneling technology and increased traffic on the aging Glenn Highway between Mat-Su and Anchorage.

PALMER – A new state study will examine whether to build a tunnel under the Knik Arm to create a second highway connection between Mat-Su and Anchorage.

The study is the latest in a series of similar proposals commissioned by the Alaska Department of Transportation over the past 20 years. It was prompted by recent advances in tunneling technology and increased traffic along the aging Glenn Highway between Mat-Su and Anchorage, according to contract bid documents released Wednesday.

The proposed tunnel would run under the Knik Arm and connect the largely undeveloped Point MacKenzie area to the Government Hill neighborhood in Anchorage, the documents state.

The study will examine tunnel costs, construction methods, engineering challenges, economic benefits and environmental impacts, among other factors. It is expected to cost at least $1 million and is set for completion late next year.

The Mat-Su is the fastest-growing region in the state and the only area expected to see continued growth through 2050, according to a recent state population forecast. More than 30,000 vehicles travel to Anchorage from Mat-Su daily via the Glenn Highway, the region’s only current connector, state traffic data shows.

“With population growth concentrated west of the Parks Highway, the Alaska Department of Transportation and Public Facilities anticipates a rise in commuter and freight traffic between Anchorage and Matanuska-Susitna Borough, as well as other northern destinations,” the documents state. “Additionally, disruptions from seismic activity, bridge impacts, and construction have increased in recent years, underscoring the need for alternative transportation corridors to strengthen the overall network.”

The state bid documents do not provide details on how a tunnel or crossing project would be funded or when it might be built.

Previous Knik Arm connector proposals developed over the decades have included a rail line, a vehicle bridge, a borough-operated ferry and a tunnel. A 2009 bridge study estimated the cost of construction at about $900 million.

In 2016, Gov. Bill Walker halted work on a proposed bridge crossing due to budget shortfalls. That order was reversed by Gov. Mike Dunleavy in 2019. The new study will be the first state-funded proposal for the project since 2013.

-- Contact Amy Bushatz at abushatz@matsusentinel.com.