What to call Darko Hreljanovic – architect, artist, designer, dreamer, urban planner?

“All of the above,” the Croatian-born Mr. Hreljanovic said yesterday.

To implement his latest project – the renewal and rebuilding of the Times Square subway station – he needs a farrago of skills. The station, after all, is the flagship of New York’s 238-mile-long subway system, which turns 101 next month. Of the 1.3 billion passengers that its trains carry each year, more than 600,000 pass through Times Square each day.

“So perhaps the word to describe my work is ‘conductor’ – or ‘composer,'” Mr. Hreljanovic – pronounced “railjanou-which” – said. “Or maybe ‘author.’ This is volume three of a trilogy that I seem to be writing.”

What’s this trilogy stuff?

“Well,” Mr. Hreljanovic said, with what could safely be characterized as a smile spawned by pride. “I was centrally involved in two earlier phases of the station’s reconstruction. I’m the only architect or designer around who’s able to say that he’s been with all of the Times Square project’s three phases.”

That involvement began some 20 years ago. Mr. Hreljanovic had already made a name in transportation design, having worked on airports, train stations, and ferry terminals. In the project’s first phase, he helped accentuate Times Square as a multilevel station.

“The idea was top allow people to move about in a more gracious way,” Mr. Hreljanovic, a partner at the architecture firm of Gruzen Samton, said.

The next phase focused on the station’s lower levels. Mr. Hreljanovic sought to graft some of the area’s street-level vibrancy onto the subterranean level by introducing shops and brighter lights.

And now he is working on the Times Square shuttle, the subway line linking Manhattan’s West Side to the East.

“It becomes personal, this kind of work,” he said. “You bring to bear all your training and discipline. You need to configure volume, light, material, problem solving.”

Problem solving was one of the first disciplines Mr. Hreljanovic acquired as an architecture major at Cornell University, which he attended after obtaining a bachelor’s degree in art history from Fordham University.

“You learn architectural technique as your career develops, you even learn the methodology in college,” Mr. Hreljanovic said. “But the ability to think – analytical problem solving – is something that must be mastered before one can start practicing. Architecture involves logic, the use of functional criteria – and it gives you the freedom to be artistic. But at the heart of the medium is taking real-life problems and situations and focusing your skills on meeting real-life needs.

“And you also need to have the ability to work with people,” Mr. Hreljanovic said. “As an architect or designer, you are engaged in meeting people’s everyday needs. You’ve got to be able to see the different possibilities – and then you need to be able to make structural adjustments in order satisfy your clients. You must not only be able to understand people’s objectives, you must be able to interpret them. To bring a project to reality, you need to sometimes step back and give up things dear to you.”

Listening to Mr. Hreljanovic is akin to attending class at architecture school. He parses his sentences carefully. He displays an economy of words. He is neat and precise in his verbal illustrations. He amiably restrains impatience at elementary questions. He’s amenable to queries about his sensibilities as an architect specializing in transportation.

“Architecture is all about how you experience space,” Mr. Hreljanovic said. “People only give thought to public buildings when something doesn’t work. So when you’re designing a train station or an airport, you’ve got to be mindful that if you’re too literal about it then it isn’t architecture – it’s just a room for processing people. I always look for the opportunity to engage the public.”

One such opportunity was his design for the transformation of Pier 79 on the Hudson River into a ferry terminal. His glass pavilion for the West Midtown Ferry Terminal, at 39th Street, wraps around the huge vents for the Lincoln Tunnel. The design, which includes elevated walkways, reflects his concern for the natural environment and for improving the passenger experience.

“I’m always emphasizing simplicity of materials – I have a natural resistance to ornamentation or gratuitous decoration,” he said.

So wouldn’t a man with such strong preferences be unforgiving about the loud styles that mark so many new buildings in New York these days?

Mr. Hreljanovic wasn’t about to be dragged into a jeremiad against the work of his peers.

“There are many styles – it’s a matter of taste,” he said.

What was the one building in New York he wished that he’d designed?

“Difficult question,” he said.

“Ah, Lever House, of course. Its clean, simple lines, its unpretentiousness. Yet it’s so much a part of the New York landscape.”

Lever House was designed by Mr. Hreljanovic’s mentor, the late architectural legend Gordon Bunshaft. The two men worked on so many projects together that they came to be known in the industry as “The Bun Squad” – a play on a popular TV show of the time, “The Mod Squad.”