People read panels with updated information about the upcoming Purple Line at an open house in Silver Spring on May 7. (Robert Thomson)

Creating a new transportation system is partly about engineering, financing and government approvals. And it’s partly a work of art.

For a decade, project manager Michael D. Madden has guided the slow evolution of Maryland’s Purple Line from a fuzzy concept for a transit line into a set of maps so detailed they had to be stretched out across a room full of tables for public review Tuesday.

Since the state decided the 16-mile transit line across Prince George’s and Montgomery counties would be light rail and selected its route, Madden and his team have been working with groups in neighborhoods along the way to solve their concerns about the line’s impact.

Madden is a man of great patience in these delicate negotiations with people looking to protect their property, their quality of life and their families’ safety. Success in talks with neighbors, government agencies and utility companies is sometimes measured in changes of a few feet on the maps.

“We’ve come a long way,” Madden said.

Map of proposed Purple Line

But not far enough for Mary Lou Carta. Since the 1950s, she has lived on Wayne Avenue in Silver Spring. During the Tuesday review session, she stared down at the detailed map that showed her house. And to Carta, it’s the devil that’s in those details. She’ll be facing the tracks and a nearby power substation.

“Why would anybody want that in their front yard?” she said.

Madden’s project team is spending May explaining the compromises reached through redesigns and why some things, such as the surface route along Wayne Avenue, have stayed the same.

Project updates

I first met Madden in 2006 when Robert Flanagan, then the state transportation secretary, conducted a media tour to point out the many engineering and human issues along the Purple Line corridor. Wayne Avenue was on the tour, and for Carta and some of her neighbors, the issues in 2013 are the same as they were in 2006.

In their cost-benefit analysis, a 21-stop light-rail link between New Carrollton and Bethesda will mar the neighborhood without making it easier for people to move about. The state did its own cost-benefit review and decided in 2009 that the surface route along Wayne Avenue beat the alternatives of tunneling under Silver Spring or using other streets.

So Madden’s work goes on. The Tuesday meeting in downtown Silver Spring was the first of five open houses sponsored by the Maryland Transit Administration.

Two more will be held this coming week, both from 5 to 8 p.m.:

●Tuesday, Bethesda-Chevy Chase High School, 4301 East-West Highway, Bethesda.

●Wednesday, Woodridge Elementary School, 5001 Flintridge Dr., Hyattsville.

Neighborhood issues

One map of the entire route spread out across several art easels highlights some of those community-by-community adjustments the project has made over the past several years. These are a few highlights:

University Boulevard. The design change where the light-rail route travels along six-lane University Boulevard is likely to be the most dramatic in its impact on travelers of all sorts. Plans had called for placing the tracks in the median of a rebuilt six-lane road. The community was concerned about the reconstruction’s impact on businesses and other properties along the way, and about pedestrian safety.

Madden said the solution worked out with the Maryland State Highway Administration after a year of study is to take the two middle lanes for the transitway, leaving a four-lane roadway in this sector. Because the roadway would not be widened, the impact on the adjacent properties would be diminished. Pedestrians would have wider sidewalks and a narrower roadway to cross.

On this part of University Boulevard, Madden said, four lanes can handle the traffic. The addition of some turn lanes also could help the traffic flow.

Lyttonsville yard. The design for a storage and maintenance yard straddling Lyttonsville Place on the west side of Silver Spring was of great concern in the neighborhood. A redesign shrinks the overall size and locates most of the yard to the west of the roadway.

Kenilworth Avenue. The line segment along Kenilworth Avenue in Riverdale Park was planned to run down the side of the avenue, allowing space for a future widening of the roadway. That created concern about the impact on nearby businesses. The updated design puts the line down the center of the avenue, with no plan for a widening.

What’s next

The project team worked out such issues with neighborhoods, other government agencies and utilities amid growing uncertainty over the Purple Line’s future. Maryland appeared to be running out of money for new projects. “We would have had to put the project on a shelf,” Madden said. “After that, it would be difficult to restart.”

In approving gas tax increases to generate transportation revenue, the Maryland General Assembly came to the project’s rescue, though the Purple Line also will need federal money. The state also has asked private companies to submit ideas on how public-private partnerships could spread the costs and benefits around.

Madden hopes the project’s final environmental impact statement will be done this summer. A favorable review by the Federal Transit Administration would put the project into its final design phase. Construction could begin in 2015, and trains could be rolling by 2020.

Or not. The Purple Line still needs specific financial commitments. Meanwhile, another Maryland transit project is advancing: Baltimore’s Red Line is planned as a 14-mile, east-west light rail link through eastern neighborhoods, across the north side of the Inner Harbor to Fells Point, Canton and the Johns Hopkins Bayview Medical Center.

The cost estimate for building the Purple Line is now $2.15 billion. For the Red Line, it’s $2.57 billion. The gas tax increase is supposed to raise $4.4 billion for new transportation projects over the next six years. Some of that money would go to statewide road improvements.

I asked Madden if it’s a competitive environment for the Purple and Red teams. “It is for me,” he said. And he smiles when he says that, but it’s unlikely these are two very expensive transitways would be built at the same time.

For an idea that’s come along way, there’s still a long way to go.