The inaugural DOC10 Film Festival scheduled to run from Friday, April 1st, through Sunday, April 3rd, at Chicago’s Music Box Theatre is chock-full of unmissable highlights. One of the very best is “In Transit,” my favorite documentary of 2015, which marks the final feature directorial effort of Albert Maysles (“Grey Gardens,” “Gimme Shelter”), who passed away last year at age 88. Completed with four co-directors—Lynn True (who also served as the film’s indispensable editor), Nelson Walker, Ben Wu and David Usui—the film weaves together a collection of human vignettes observed on Amtrak’s Empire Builder as it chugs along the Pacific Northwest. When I covered the film upon its AFI Docs premiere, I noted that none of the individuals onscreen are identified by name, which I felt was appropriate. This film is an ode to all the nameless souls who leave a lasting impact on our lives in the brief time we share with them.

In the spirit of their seamless collaboration, True and Walker submitted the following answers via e-mail to my questions about their experience working with Maysles on this sublimely crafted project.

When did the concept for “In Transit” first come into fruition?

The concept is one Albert Maysles had had for decades. From his own travels, he was inspired to make a film that showcased the unique space of the long-distance train where he had so often witnessed people from all walks of life come together and find common ground.

How did you become involved in the project, and how did Albert pitch his vision for it to you?

Albert was a fan of our previous films, which use a Direct Cinema approach very similar to his, so he asked us to collaborate. Al had been pitching this project to pretty much everyone he met over the last 30 plus years, so we were already pretty familiar with it and excited by his vision, which was simply to board long-distance trains, meet everyday people and follow their stories. To fill out the team, we suggested bringing on our friends and fellow filmmakers, Ben and David.

What was the process like of searching for potential subjects while abroad the train, capturing candid moments without becoming intrusive?

While we were shooting, we immersed ourselves in the culture of the train, and thought of ourselves more as fellow passengers than as filmmakers on a mission. In practical terms, this meant sharing ourselves with our subjects, and taking a laid back approach to filming. There were amazing people around us, and in many instances, all we had to do was strike up a conversation. We also had a secret weapon in Martha Wollner, our undeniably charming story producer. She would walk the train and talk to the passengers—if they seemed interesting and interested in being filmed, she would connect them with one of our shooters.

How did you go about coordinating the responsibilities for each director during production, and how many trips did you end up taking on the Empire Builder?

There were four shooting trips in total—three on the Empire Builder and one road trip where we drove across country along the route filming exterior shots of the train going by. Because the train is such a dynamic space and there are so many variables, we attempted at first to exercise some control by assigning each director a specific area to film, like focusing on the Observation Car or the Sleeping Car. But pretty quickly, it became clear that there are too many moving parts on a train, and we all just had to go with the flow and follow passengers and stories wherever they led.

What visual approach did Albert want David, Nelson and Ben to utilize in their approach to the film’s cinematography?

Albert never pushed any sort of visual approach, mostly because our team already had an intimate understanding of what he was after. Pretty much everyone on our team had worked with him in some way in the past, and we’re all deeply influenced by his work. During the filming of “In Transit,” Albert was concerned more with substance than style. He wanted to capture truthful moments of people finding common ground, whether between the cameraperson and the subject, or two complete strangers meeting and becoming friends. True to the classic Maysles approach, this necessitated using small cameras, natural light, and unobtrusive sound recording.

What particular interviews stood out to you as defining moments for the project as a whole? I mentioned in my review that the photographer felt like a poignant representation of Maysles himself, especially when he reflects, “I know I’ll never be out here again. It’s been a good trip.”

One of the nice things about “In Transit” is that almost every subject in the film offers something that can be taken to define the project as a whole. The interview with Joel, the photographer, is obviously very poignant. Albert and Joel were on similar journeys, riding the train to see the world around them and connect with others while they still could. Another interview that stands out is with Roxy, the young woman in the knit hat who was raised by drug-addicted parents. She turns to the camera and says something to the effect of, “These are the things in my head that I don’t tell other people. I shouldn’t be telling you these things. They are the secrets to life.” This moment is a great encapsulation of the spirit of Albert’s filmmaking. He had an uncanny gift for connecting with people, and an ability to make them feel safe in sharing their deepest hopes, fears, and dreams.

How did your vision for the film evolve in the editing room? It is one of the most extraordinary achievements in editing that I’ve seen.

The priority was always for human stories to drive the narrative, not the geography or chronology of any specific trip. It was a huge challenge to find a balance that allowed us to jump between so many individual stories occurring on different trains without disorienting the viewer. Eventually the structure evolved to mirror the three days it would take to get from one end of the route to the other: the first day generally includes stories from the vantage point of someone embarking on a trip, looking forward into the future, anticipating the unknown; the second day uses stories from the perspective of passengers who have settled into their ride, and now have time to reflect a bit on where they’re coming from, what they’re leaving behind; and the third day involves stories colored by the energy that comes from the inevitability of having to de-train, face reality and return to normal life. I thought of it as a “future-past-present” structure.

How has the experience of working with Albert enhanced your own approach to filmmaking, and what has his work meant to you?

Working with Albert on “In Transit” was a great honor. It was a film that he had been dreaming of making for decades, and each of us felt so privileged to help him finally bring it into being. One of the biggest lessons we learned from Albert was to have patience and trust our subjects. When we were in pre-production, we briefly discussed the idea of finding interesting subjects and planting them on the train. Albert would have nothing of it. Our subjects, he said, are already on board. He saw possibility in everybody, and taught us that if we approach our subjects with love and kindness, we will find truth.

Below is a transcript of the letter Maysles distributed to passengers aboard the Empire Builder, which coincidentally included Table XI’s Josh Golden, web developer at RogerEbert.com, who wrote about his encounter with the filmmaker last year.

Josh Golden and Albert Maysles.

Strangers, fellow passengers on this train, who are you? What did you leave behind? When you arrive at your destination, what lies before you?

If life is a journey, we are all fellow travelers. When I have journeyed on trains, I have seen people come together who in no other way would possibly meet. On trains, we discover a unique intimacy, where normal conventions dissolve and we open our lives to complete strangers. Maybe it is because the train holds us in limbo, a moment of truth between stations.

For over thirty years, it has been my dream to make a film about trains. Really, it is a film about the unity of humankind, in which viewers come to experience directly the feelings, hopes, and problems of others. And through this process of getting to know each other, we build the foundation for loving one another.

The film I am making is not a news piece or reality TV. My aim is to capture the human experience of train travel, and the unique community that emerges on trains. I will film my fellow passengers having conversations and making new friends, but also during quiet moments as they read, sleep, or daydream. Eventually, the film will appear on television, but the details of when and where are still being sorted out.

In making this film, I have embarked upon a journey of my own. For me, it is a moment of decision and truth that will unfold on the train. I hope to share this moment with you, and hear your stories as well. Together, we will create a tapestry of universally understandable episodes that are proof of our common humanity—in short, a real life epic.

So let’s take advantage of our time together, and get to know each other on this journey.

Lynn True and David Usui are scheduled to attend the 1pm screening of “In Transit” on April 3rd at the Music Box. For tickets, visit the venue’s official site. To read my preview of this year’s DOC10 festival, click here.