"Tom was in the vehicle on a low-loader."

Film Joke all you want about the title of Locke, Steven Knight's car film with Tom Hardy ("What he lives? Was it time travel? How did he get off the island?") but the production process sounds intensely interesting. Here's a short interview with Knight about it from Little White Lies:

"LWLies: We understand you shot the film 16 times and edited it together from those takes?

Knight: Yeah. Normally when you make a film there's a good reason not to do the obvious, it can be a very frustrating process. With this, having a certain level of control, I almost wanted to do it in a very naive way. The story of a man's journey and his life unravelling is there, so in practical terms what I did was put the rest of the cast into a hotel conference room, near to the motorway, opened the phone line to the car. Tom was in the vehicle on a low-loader. I would be cueing the calls in sequence, and we shot the film from beginning to end, all the way through, 16 times. We were basically shooting whole films in sequence."

Production wise this doesn't sound as problematic as Mike Figgis's Timecode in which essentially this was done four times simultaneously and without any breaks in filming and with a massive cast. But Locke seems like it will have less artifice, is edited to look like more standard fare, and that's probably the more interesting process in terms of dealing with the material. How can you tell which take to use if the takes are half an hour long?