Why is the public transport (metro rail) in Mexico city so popular?

Yeah... all that is true, but it's not so wonderful, it depends on your life style. For example for me it's a nightmare because it's too crawled, in some zones is dirty, the food is junk usually, most of the people is rude (because they're late or something), and even though there's police, delinquency is very common. If I had to use it every day, I would become mad.

Because it's very very cheap and effective, there are metro stations in lots of places and sometimes you can even eat there, there are all kinds of food sellers, like tacos and mexican food. Everyone can use it, it's just like 1 mexican peso each ticket. And it's way more cheap than taxis or buses, and buses are slow because of all the damn traffic in the city.

Popular?? because it was in the movie Total Recall, with Arnold Schwarzenegger. Also, as the roads are extremely crowded most of the day and night.. It is an easier and faster way to get around. I have hit bumper to bumper traffic late at night on a Tuesday night.. so no concerts, way after work time traffic.. no obvious reason for the traffic except that there are just tooooooooo many cars on the road. Also, you are not ALLOWED to drive your car on certain days of the week.. Depending on you license plate number.. for example, if it ends in a 0 or 1, you can't drive on Monday.. 2 or 3 you can't drive on tuesday, etc.. (i didn't look at the table, and don't know the exact days for which numbers) I did see the table when renting a car, and the rental car agencies have to stick to the law as well.. So they can only rent certain cars on certain days.. I wonder what they do if you'll be in town for the whole week or more.. So, since roads are very crowded, that also plays a role in buses and taxis.. (which there are way too many of as well) Speaking of railroading.. I am surprised that Mexico does NOT have a railroad system (nationally) They used to, but not anymore..

Because of Mom of 3's answer is missing some details that are vital to your report. First and foremost, the metro rail is by far the best way to go from one point of the city to another part. As for its cost, it costs to ride it less than 1 US dollar in either direction. It is very much safe because it will save the wear and tear of the car. Please do not forget that the cost of the gas is 40 pesos for a quart of gas. Do your math and you will find out if the car normally takes 20 to 30 gallons worth then we are seeing a lot of money leaving our pocket books. Secondly, it is popularity is increasingly due to the major fact that the Mexicans who have to travel prefer to use the metro rail for safety reasons. Once aboard the metro, you will feel very much safer and arrive healthier.