The state Department of Transportation is proposing to add two additional vehicle lanes and shared shoulders to Puunene Avenue between Wakea Avenue and Kuihelani Highway. The popular roadway is frequented by residential and visiting drivers, bicyclists, pedestrians, public transit and emergency response operators, as well as freight system drivers.

“The purpose of the project is to reduce the congestion and improve the traffic flow along Puunene Avenue,” according to the final environmental assessment released Thursday in the state Office of Planning and Sustainable Development’s “The Environmental Notice.”

Puunene Avenue currently extends approximately 1.2 miles from Kahului Bay near the east side of Kahului Harbor to Kuihelani Highway before transitioning into Maui Veterans Highway.

The project area, which covers 0.6 miles, or roughly half of Puunene Avenue, is mostly residential with a combination of paved and unpaved shoulders along both sides of the road.

DOT is proposing to construct new sidewalks on both sides of Puunene Avenue, linking Wakea Avenue to Kuihelani Highway.

Bioswales and a shallow underground drainage system would be installed, too, along the length of Puunene Avenue to improve water quality and reduce the impact that roadway stormwater would have on the existing drainage system, according to the report.

Traffic signal poles at Papa Avenue would be relocated to accommodate the roadway widening and street lighting will be added.

“The goal of this action is to provide safety improvements for both drivers and non-motorists along Puunene Avenue,” the report said.

With the widened roadway, vehicles will no longer be able to park along the shoulders or the unpaved areas within the right-of-way.

Depending on the availability of resources and funding, construction is anticipated to begin this year and be completed by late 2025. Work is expected to be conducted in three phases so that only portions of the roadway would be affected at one time.

Construction costs would depend on the final design and winning construction bid, but preliminary estimates indicate that the bill would be around $15 million and financed by federal and state funds.

* Dakota Grossman can be reached at dgrossman@mauinews.com.