American Honey only features a few professional actors — Riley Keough (Mad Max: Fury Road, Magic Mike) as Krystal, the mercenary head of the mag crew, and Shia LaBeouf as Jake, her top seller and trainer. But the real revelation is first-time actor Sasha Lane as Star, a runaway who falls for Jake the first time she sees him, and joins his crew’s cross-country ramble to get closer to him. I recently talked to Arnold about her casting and shooting methods, and the night she rescued a drunk kid from the police.

Andrea Arnold’s new film American Honey is a fascinating, immersive trip across the American heartland with a crew of hard-partying 20-somethings, but it’s also one of those projects where the behind-the-scenes story is as compelling as the one on-screen. Arnold, the British director of Fish Tank and Red Road, prepared for her first American movie with an extensive cross-country road trip. Along the way, she looked for the young people she wanted to cast in her film, finding them at beach parties and hanging out in parking lots. Arnold had read a 2007 New York Times article about mag crews — traveling groups of young people selling magazine subscriptions, often for predatory companies keeping them indentured under brutal conditions. She wanted to make a film about a mag crew, but she wanted the performances to be authentic and natural. So she effectively built her own crew out of young people she found while traveling. Then she loaded them into a van and took them on a 12,000-mile road trip, encouraging them to bond and interact naturally while she shot the film around them.

Why did you decide to use non-professional actors for this film? Why was it important to you to find them in their own scenes and parties around the country? I do a lot of my films this way, using people who haven't acted before. But on this one, it seemed even more important somehow to represent the kind of people that join mag crews. Seeing those authentic faces felt really important to me. So from the beginning, I wanted to use real people whose faces summed up that life. I'm always trying to do things as authentically as I can, as much as possible. Doing a real road trip and taking everybody together felt like a way of having a real experience, as opposed to pretending to have an experience. I always wanted, literally from the beginning, for the cast and crew to go on a trip together. There wasn't this usual thing where you might do a couple of weeks filming in one place, and then fly to the next, and somebody will fly in for two days, and fly back out again. I wanted us all to have a real experience. So the crew and all the cast met at the beginning, and we went on the whole trip. We traveled and stayed in the same motel, and had a real experience together. We lived together, we were making the film together, so it was a proper adventure. I think doing that meant that the film has more of a realistic feel. How firm was the script when you started? Are there parts of the movie that you just discovered on the road? "Everyone thinks, 'Oh, is it a documentary, is it a drama?'" There was a script. Everyone thinks, "Oh, is it a documentary, is it a drama?" There was a script, but what I do a lot is, when I learn things, when I cast people, I go back and revisit the script, and I might change it according to what I've learned. I think maybe that's what people are reading. It seems quiet, like it's off-the-cuff. Some of it is improvised. Like the scenes in the van where we're actually traveling, we would film everybody. When we moved locations, as we drove out to the next state, for the next place where we were going to stay, even though that wasn't in the script, we'd film inside the van. So some of those scenes in the van when we're traveling are just what was happening, just us hanging out. I'd give them some notes. With Sasha, who is playing her character, I would definitely give her notes, because I wanted her to be at a certain stage of her journey for each scene. For her, that was quite hard, because they're all partying all the time, and she wanted to party, but I wouldn't let her. That was particularly tough on her, because I always wanted her to be kind of thoughtful or sad, or thinking about Jake. Everyone else is always singing and dancing, and she wanted to join in with them, but I had to sometimes stop her doing that.

What else did you do to help her build that character? I cast quite close to what I'm looking for, so I'm not wanting anyone to be necessarily different from who they are. But at the same time, they're saying my words which I've written, and they're wearing clothes I've given them, and they're standing in locations and taking part in scenes that are nothing to do with who they are as real people. I put them in my situations, then I don't really ask or want them to add much more. Star is a bit more country than Sasha. Sasha is more worldly and had more education and is a bit more urban than Star. And she dresses differently. All I asked was that she dress a bit more country, and not say certain words. And then off we go, really. What kind of cameras did you use? We were gonna shoot on film and video. Robbie Ryan is a fantastic DP, and he's a huge fan of film. So am I. We actually did some testing in London — we have a picture from London of all the 10 different cameras we were going to test. We've got everything from a tiny little camera up to the 35mm cameras. Robbie knows what all the cameras were, but when we were looking at footage, I didn't want to know which cameras went with which shots. I wanted to pick what I thought was right for the film without knowing what the camera was. And without a doubt, what came in completely at the top was 35mm. It gives such a great surface. We didn't have any of the cast at that point, so we just filmed a lad we knew. And the 35mm gave him such presence. I can't really explain it any more than that. More than just, without a doubt, I wanted that. The one after that I like the most is the Alexa, which is what we ended up shooting most of the movie on. When we started off, we were going to do a mix of both, because we couldn't afford just film. We started at the beginning. I had an idea that maybe all Star's close-ups were on film, and the rest of it wasn't, so she'd really feel present in the scene, visually. But then when we got going, it was so challenging. Digital was just much easier — we were getting more out of being able to keep rolling on the digital camera and not having to stop to change [film cartridges]. I would never say there's a downside to using film, but working with non-actors, it's probably easier just to keep rolling. One of the more insightful reviews I've read of the film says people don't really process youth when they're young, so movies like this are more for older people who want to remember an experience they weren't conscious of at the time. Does that idea speak to you at all? I can see that. When we're young, we're dealing with so much. I think that's life. Maybe when you're older and you're looking back at being young, you can see it more clearly. When you're young, you're still going forward, and you don't quite know who you are, and you're not reflecting so much as just being in it. Certainly when I was the age of the people in my film, I would just kind of barge through life, not really reflecting much on anything. Just living in the moment.

How did you end up with the 4:3 aspect ratio? It's an artistic decision. I've done my last three films with the same ratio. It's a ratio I much love. My films are usually about one person and their experiences of the world. So I'm mainly following them around, filming them quite closely. And it's a very beautiful frame for one person. It frames them with a huge amount of respect. It gives them kind of honors, the human in that frame. I was very attracted to it when I first started making films, but I wasn't able to articulate it and understand why I was doing it until later. But now I understand, that respect is what it's about. Shia LaBeouf is intense about method acting, and his recent road-trip art project seems highly compatible with what you did with your own filming road trip. How did his process work with what you did on this film? He fitted in the way I wanted to work just so smoothly. I met him early on and I talked about the way I wanted to work, and he was really, really, enthusiastic about that. He really liked all the things I was saying. I think maybe we're quite similar in the things we care about in that way. We did have a good working relationship. I mean, he had to come into a group of people that were real people, and that must be quite challenging for someone who's done lots of acting, because you know he had to try to be quite real, just to not stand out from all these people who are just themselves. And he did that, which I think is pretty remarkable. Do you have any particularly memorable stories from the period where you were just going to beach parties and Walmart parking lots, looking for people for the film? It was always eventful. I suppose the time I remember the most is being on Panama City Beach during Spring Break, because it was so lively. My absolute favorite thing was to sit in the Walmart car lot on the beach at Panama City, and just watch all the kids come buy stuff and head out to the beach again, or sit in their cars and play music. It was just the liveliest play. I felt like it was such the place to be, there was no better place to be in the whole of Florida than that Walmart car lot. And they're dancing and twerking, amazing kind of twerking going on. [laughs] Fantastic dancing. I could sit there all week and just watch everybody. We were driving around looking for people, and we found so many people in distress, because they were drunk, lying on the road. We ended up as a bit of a rescue service, because we picked people up on the road and took them back to their hotels. That happened quite a few times, because there's an awful lot of drinking going on at Spring Break. We stopped a guy from getting arrested. He was just such a sweet man, but he was completely drunk, running around 7-Eleven. They wouldn't let him in, and the police came and were going to arrest him. We said, "We'll just take them home, he's just pissed." And they said, "What's he pissed at? What's he pissed about? Why is he pissed? What's he been doing?" It took me a while to realize that pissed in America means angry, while in England it just means you're drunk. But we got him home. I remember a lot of drama in Spring Break in Florida. And where else? We were in West Virginia a lot, wandering state fairs, I remember being in Upstate New York, staying at Motel 6, having breakfast in Denny's, then looking for people in state fairs.