Other key tips about Metro use.
-Unless you are at one of the wide gates, the gate does not have to close before you can swipe your card. just walk through the already open gate and swipe your card. The gate will stay open. The wide gates can be access from both sides, so they close between uses.
-Don't stop as soon as you step into or out of the train. Tourists tend to not know where they are going, so they tend to stop immediately after taking one step out of the train and try to read the signs to figure it out. Step out of everybody's ways first, then try to figure out where to go. Also, tourist seem to stop as soon as they enter the cabin. Realize people have to come in behind you so clear the door ways.
- Metro is very safe, but be street smart. Don't leave your purse, bag, or phone somewhere it is easy to grab and sit close to the door of the train.
-If you are worried about riding the train late at night, pick a car in the middle of the train as these will always have more people in them. If you are near the front or the back of the train, it can get pretty desolate.
-Learn to ignore people. If you get onboard with some one with mental issues or that is making a general ruckus (loud teenagers, drunks, etc) don't try to stare them down or confront them. This will often make it worse. If it is bad just switch cars at the next station.
Have fun.