An urban expressway linking two interstates. A sunken linear park. A two-lane city street and greenway.

What to do with St. Paul's Ayd Mill Road has agonized generations of city leaders. With the pothole-plagued 1.5-mile street turning into a bumpy mess, Mayor Melvin Carter has pitched the latest vision: a thoroughfare shared by pedestrians, bicyclists and motorists.

Once called the Short Line for the railroad tracks that run adjacent to its bone-jarring traffic lanes connecting Interstate 35E and Selby Avenue, Ayd Mill Road's transformation depends on whether the City Council bolsters a $3.5 million repaving with another $1.6 million to redesign and re-engineer it. Carter wants to reduce Ayd Mill from four lanes of 45 mph traffic to two lanes, along with bike and walking trails.

As it has for most of its 50-plus years, Ayd Mill Road is caught in the middle of those who seek a convenient link between two stretches of busy freeway and those who want to return it to a quieter, calmer combination of street, trails and green space.

"I think this redesign can impact the neighborhood in a positive way," said Zachary Tiffany, a resident of nearby Union Park. "Besides, Ayd Mill Road doesn't need four lanes of capacity."

Ian Buck, a Frogtown area resident who is co-chair of the St. Paul Bicycle Coalition, said Carter's plan is music to bicyclists' ears.

"It would be a perfect connection to the Midtown Greenway [in Minneapolis]," he said, adding that reducing traffic to two lanes shouldn't have that much impact on vehicles driving through the area.

Lisa Raduenz, a Macalester-Groveland resident, vehemently disagrees.

Raduenz has worked for 30 years in transportation services and as a transit planner. She says the proposal is short on analysis and would be downright dangerous for bicyclists on Ayd Mill and neighboring streets that will fill with diverted traffic.

"You're just asking to get someone killed," she said.

Carter wants Ayd Mill to become part of an alternative transportation network that reduces reliance on cars while promoting greener ways to get around.

"These efforts will result in a road that is less expensive to maintain and more useful to residents moving around our city in different ways," Carter said when he announced his 2020 budget two weeks ago. "We all know that some will mock the notion of investing in sidewalks and bike lanes, but here's the simple truth: Our city has grown by nearly 30,000 people since 2010, and we are projected to add another 30,000 over the next 20 years. Unless our local streets can absorb 30,000 more single-occupancy vehicles than we have today, our only choice is to fundamentally shift our ideas about how people get around our city."

As envisioned, the project would transform the two northbound lanes of traffic into separated 13-foot bicycle and pedestrian pathways. The southbound lanes would become two two-way traffic lanes, taking vehicles to and from I-35E, said Public Works Director Kathy Lantry. Signal lights, turn lanes and connections to nearby streets (Ayd Mill runs in a below-grade trench) need to be designed and engineered, Lantry said.

Lantry said that turning Ayd Mill Road into a multiuse transitway was approved by the City Council in 2009 but never implemented. "It is current city policy, and that is what we're going to do."

"This is not about getting rid of cars," she said. "This is about giving people options and choices."

Ayd Mill history

The road runs through a ravine once belonging to John Ayd, a German settler who operated a grist mill at a nearby pond in the mid-1860s. By the late 1870s, the Chicago, Milwaukee, St. Paul and Pacific Railroad had bought a right of way and built the "Short Line" through the ravine. While there was talk of building parks in the area even then, it remained exclusively a rail route for decades.

By the early 1960s, the Short Line road was built with the idea of linking I-35E in the south with I-94 to the north. Neighborhood opposition to the completion of I-35E delayed that project, however, and stymied the connection. Between 1965 and 1992, the road carried very little traffic. The city built a ramp connecting Short Line Road to I-35E, but it was unused. In 1993, the city changed the street's name to Ayd Mill Road.

George Latimer, mayor of St. Paul from 1976 to 1990, admitted he had no appetite for a fight over what to do with the road.

"Someday, I'm going to write a chapter of my book called 'All The Issues That Latimer Ducked,' " he said. "I seriously ducked it."

He said Carter's plan is not a bad one, but he understands the resistance.

"It is part of our whole wonderful parochialism in St. Paul," he said. "We love places that we lived near, and we want them to stay the same. We don't like change. And, if you live on a side street, you like the quiet."

In 1999, despite a task force calling for the road to be remade into a park, the St. Paul Planning Commission made a four-lane road extending north to I-94 the preferred alternative. In 2002, Mayor Randy Kelly connected Ayd Mill to I-35E, a move that almost immediately eased traffic that had been tying up streets to the south.

But it was never extended to near I-94 to the north, which would have required the purchase of several parcels of land. Traffic to the north still spills onto Selby Avenue.

Jay Benanav, who served on the City Council around that time and ran for mayor in 2001, said the whole idea was to create a shortcut between the freeways and ease traffic congestion in surrounding neighborhoods.

"From the beginning, it was controversial," he said.

Then, in 2009, with Carter on the City Council, it unanimously passed a resolution stating Ayd Mill Road should remain a city street in perpetuity and that the city should explore reducing it to two lanes and creating a greenway.

Earlier this year, the council voted to spend $3.5 million to repave the notoriously rough road, drawing criticism from those who favored a more comprehensive approach.

Then Carter made his pitch Aug. 14.

Benanav called it "a brilliant compromise," saying that "at some point we have to do something with Ayd Mill. It's a disaster right now."

Given the road's history, change won't come quietly.

James Hamilton, a Macalester-Groveland resident for more than 35 years, said he has written to the mayor and Council Member Chris Tolbert to demand public hearings before they do anything about bike trails.

Traffic on area streets at the south end of the road "was horrific" before it opened, he said. "When Kelly opened it up, it really relieved the congestion."

Now, with a surge in development near Selby and Snelling avenues, it's time to address traffic tie-ups at the north end of the road, Hamilton said. Like finally connecting it to I-94.

"People are frustrated by decades of traffic and an ongoing pattern of manipulation by the city to do what they want to do with a minimum of public interference," he said.