PORTLAND – The oddly shaped mounds of earth that have sprung up along the Marginal Way end of the Franklin Arterial are just the latest evidence of the transformation occurring in Portland’s Bayside neighborhood.

Look closer and you’ll see work crews laying bricks, and a ribbon of pavement on the abandoned railroad right-of-way between Marginal Way and Somerset Street. Those mounds will be soon be covered with grass, an ideal perch for lunch on a sunny day.

By the end of June, a mile-long trail will connect the Back Cove and Eastern Prom trails to Elm Street. By next spring — if trail supporters can raise another $1.6 million — this will be an urban greenway, complete with pocket parks, benches, public art, playgrounds and gardens.

After more than a decade of planning, the nearly $5 million Bayside Trail is taking shape.

Trail advocates say the project amounts to an extreme makeover for one of the most blighted urban landscapes in Maine. The end result, they hope, will be a lively urban neighborhood, a modern extension of downtown Portland. Moreover, the trail will serve as both a public gathering place and a key link in Portland Trails’ network of 30-plus trails in Greater Portland.

“We are creating in the middle of Bayside this little oasis,” said Mark McAuliffe, managing partner at Apothecary by Design, located near the trail on Marginal Way.” If you are a business looking at this area, this is a tremendous attraction.”

Some of the nearby landowners believe the trail will make their lots more attractive to developers.

The trail follows the old Union Branch railroad easement. The route — particularly the desolate stretch in East Bayside, has had a reputation for being a high-crime area.

But that’s already changing as trail workers clean up, said Doug Cardente, who owns at least six acres abutting the trail. It’s going to be even safer when it’s completed and lights are installed, he said

“The trail is going to be a huge benefit to the city, even if it’s mildly used,” he said. “It’s so much better than it was before.”

The city owns five developable parcels totaling about 10 acres. Before the economic downturn put a halt to some proposed projects, developers could only imagine the trail’s benefits, said Alex Jaegerman, director of the city’s planning division. The trail’s completion will make it easier to market the area once the economy recovers, he said.

Not all public parks improve property values, cautioned Kevin Bunker, a developer who is now building housing for medical students near Maine Medical Center. One acknowledged failure, he said, is Congress Square, which the city turned into a bricked park in 1979.

“It’s unused urban space that was planned with the best intentions,” he said, “but it didn’t work out so well.”

Still, Bunker is optimistic for the Bayside Trail. He said the critical question is whether users will feel they are safe when they use it to bike or walk home at night.

The trail is being built wide enough so police cars can use it in emergencies. Also, some of the fencing will be removed and access opened up so users won’t feel they are in an enclosed area, said Jim Gooch of the Trust for Public Lands, one of the project partners.

The city purchased the former railroad property in 2005 for $1.5 million. The rest of the money came from a combination of federal and state sources, including $800,000 in stimulus funds.

In the second phase of the project, the city plans to extend the trail to Deering Oaks when it rebuilds Somerset Street.

The rail yard, located west of Franklin Arterial and between Marginal Way and Somerset, was constructed in 1910 in a former swamp that was filled-in. The yard was taken out of service in the 1980s.

Two-thirds of the money has been spent to improve the drainage in the area and to remove or cover up contaminated soils with 18 inches of clean soil.

The mounds of earth on each side of Franklin Arterial serve dual purposes: They cap contaminated soils, and could also serve as potential ramps if the city can find $5 million to build a pedestrian bridge over Franklin Arterial.

In the meantime, trail users will have to cross the four-lane state highway at the traffic lights at Marginal Way.

Some urban designers say that a meandering trail seems more fitting for the suburbs than the city. While connecting the Eastern Prom Trail to Deering Oaks is important, the city should have built bike lanes and sidewalks and preserved the urban grid, said Mitch Rasor, a land planner based in Yarmouth.

Rasor said an urban grid creates more engaging civic spaces and allows for more efficient use of land for development.

But developing every square foot of land is not the goal, said Ron Spinella, president of the Bayside Community Development Corp.

“From an economic standpoint, it’s not about getting every last inch of earth and putting a building on it,” he said.

“There are other gains you can achieve by having a pedestrian infrastructure in place. Maybe I’m a dreamer. But I know I’m not alone. I’m in good company.”

 Staff Writer Tom Bell can be contacted at 791-6369 or at: tbell@pressherald.com