Portland is preparing to begin the long-planned overhaul of a landmark downtown intersection that also is one of the city’s busiest crossroads.

The city announced Tuesday that work on the $2.5 million first phase of a redesigned Congress Square is expected to begin in July and be mostly finished by November.

The first phase includes reconfiguring the intersection of Congress, High and Free streets to improve traffic flow, upgrade signal equipment and enhance safety for motorists and pedestrians, the city said. Changes intended to enhance pedestrian safety will include eliminating one entrance to Free Street and expanding the pedestrian plaza in front of the Portland Museum of Art.

The second phase of the project will include improvements to Congress Square Park and additional street-scaping, but won’t get under way until at least 2022, the city said.

Congress Square lies in the heart of Portland’s downtown commercial and arts districts, and is the crossroads of two major roads bisecting the Portland peninsula. Planners have discussed improvements for years to manage the flow of commuters across the peninsula and the desire of locals who want to enhance safety and reconnect the neighborhood.

“We’re really delighted with the intersection design as it stands right now,” said C.J. Opperthauser, the executive director of the Friends of Congress Square Park. “What we really value most about it is it really prioritizes the experiences of people, and space for people rather than space for cars.”

The intersection in the heart of downtown Portland can be a problem for pedestrians. An average of 14,000 vehicles a day use the High Street approach, more than 9,000 vehicles use the Congress Street westbound approach and 3,200 take Free Street. 2013 Press Herald photo by Gabe Souza

Emma Holder, president of the Parkside Neighborhood Association, said residents often walk through that intersection and spend time in the park. She said the design is a step in the right direction.

“For me, the most important part about this is that it’s just starting to equalize all travelers to the same level of importance of getting around,” Holder said. “It’s not just the single-driver vehicles that are being thought about here.”

During past discussions and studies, the city has considered converting both High and State streets into two-way roads to help improve pedestrian safety and slow traffic. However, the work beginning this summer will maintain one-way traffic on High Street and there are no plans to move forward with that project at this time, City Hall spokesperson Jessica Grondin said.

“The design doesn’t include or preclude (two-way traffic), but with the current and future necessary infrastructure projects in our pipeline, there is no funding for this project,” Grondin said.

The intersection can be a tricky one for pedestrians. An average of 14,000 vehicles a day transit the High Street approach, more than 9,000 vehicles use the Congress Street westbound approach and 3,200 take Free Street, according to the Maine Department of Transportation.

Mike Tremblay, a senior engineer with the city, said pedestrian safety will be improved by reducing the width of streets people must cross, while also slowing down traffic entering Free Street. Also, traffic signals will be improved so they can adjust to traffic demands, he said, which should prevent westbound backups on Congress Street.

The most dramatic change will be eliminating one Free Street entrance and moving the remaining entrance 80 feet east of High Street, as well as changing the angle, to provide safer pedestrian crossing and to slow vehicles down as they enter Free Street.

“A segment of Free Street will also be raised, further encouraging slower traffic speeds,” Tremblay said. “Pedestrian safety will be increased due to this slower traffic.”

The rendering does not show any new bike lanes, but Opperthauser said the area will become safer for cyclists as well.

“One of the big outcomes is simply slowing down car traffic, and that sounds really simple, but it is really the biggest enhancement to bike safety that you could achieve outside of dedicated space for bicyclists,” he said. “Slowing down traffic will really help for every single mode of transportation.”

Eliminating the right-turn slip lane from High Street will make room for an expanded plaza in front of the Portland Museum of Art, the core of the Congress Street arts district.

Free Street traffic will remain one-way in the current easterly direction. He also said on-street parking on High Street would not be impacted.

The second phase of the project, which will not get underway before 2022, will include improvements in Congress Square Park. The new plaza in front of the art museum is expected to be improved as well.

Opperthauser said the intersection will be more cohesive and accessible, especially for people who are using a wheelchair or pushing a stroller.

“This will add a whole new vibe and sense of life to the events that we do now and whatever events we do in the future,” he said.

The city is planning to install a piece of public art by New York City artist Sarah Sze in Congress Square Park. That will be included in the second phase of the project.

The city said its Public Works Department expects the project to go out to bid in May, begin construction in July, and substantially conclude in November. The announcement did not include more details about the construction plans, including detours or road closures.

The Maine Department of Transportation is providing $1 million for the project and the $1.5 million balance is coming from the city’s Capital Improvement Program and other city funding sources, the city said.