I think the woman had been held hostage, maybe by government officials? She gets into a taxi under a bridge, I think he asked for some kind of ID card or something that everyone has and uses for everything. I think the taxi driver was black and I think she was wet. I think she had escaped by swimming through the water, and then found his taxi when she pulled herself out of the water under the bridge. He asked her what her name was, and she didn't remember. She looked at his drivers license, and told him she knew where he lived and threatened his family if he didn't help her. It might have been a futuristic dystopian society. Took place in a big city like New York or Chicago. In the end, she tells him he's free and goes to confront her kidnappers (in a lighthouse?) but he decides to follow her, because he knows what they did to her and wants to help. Had a happy ending, I believe. I really want to know what movie this is. I think it came out around 2000-2010, definitely not in black and white.