Paul Greengrass gets major props for what he went through to do some scenes in The Bourne Ultimatum. According to Rotten Tomatoes, an already-talked-about Waterloo chase scene was shot without shutting down the station for the film crew, which would have been logistically impossible.
From the RT article:
“What you do is you design the sequence that is in many, many pieces so in fact you’re planning to shoot in many different parts of the station,” said Greengrass. “What you have to do is never be in the same place twice because what happens is that people get to know you’re there and a crowd starts to build up. It’s impossible to be like a true guerilla unit because it’s a huge, it’s a Bourne movie, but you’ve got to move from place to place and be unpredictable so people don’t know where you are and then move on fast.”
The sequence lasts several minutes and took many days to shoot, but Greengrass scheduled those days tactically. “You’ve got to schedule it so you’re not there for too long a period of time in any one time. So you might go for two or three days and then disappear and go off and do something else and then come back for two or three days a week or two later. If people get to know you’re going to be there, then the crowds are going to build up.”
That meant Matt Damon has to be ready whenever there was a brief window to shoot a corner of Waterloo. “It puts prodigious demands on the actors because they never know from one hour to the next which bit of the sequence [they’re shooting]. Even I didn’t know. You’ve just got to seize your moment. It makes for opportunity.”