What is Mary doing at the beginning of the talk?

M: Hello, Mary. Why are you standing here?
W: I’m waiting for a bus. The buses are so full at this time of the day.
M: Sure. Where are you going? I don’t think this is your way home.
W: You are right. I’m going for a walk in the park.
M: Going for a walk even after along day’s work?
W: Yes. I always enjoy walking alone in the park after work.
M: I see. Then why not go there on foot? It’s not so far from here.
W: Oh, no. I hate walking through the streets.