Mastering London's Underground System
Compared to the other places I've been, I feel very comfortable saying that London's transportation system is unparalleled. Of course, I haven't been to every country in the world and tried out each different transport system but, so far, no other place I've visited has even come close to matching London's organization.
The tube system is broken into colors, making it very easy to navigate without much assistance. I'd say that I'm an expert - if not close - in using the tube system, and I've only been to the city a handful of times so far. That's how easy it is to comprehend.
London is divided into nine "zones" that are designated by their proximity to the city center. For instance, Zone One consists of stations like Piccadilly Circus, Leicester Square, Covent Garden, etc. that are located right in the heart of London. Alternatively, the outer zones, such as Zone Six, consist of stations for the Heathrow airport, located about an hour from the center. The farther you travel from Zone One, the more your fare will be.
The most common method of payment is called an Oyster card, London's exclusive transit card. Every train station has ticketing machines where you can buy an Oyster card as well as top-up an existing card when your balance is getting low. If you're planning on using your Oyster card for quite a bit, you can register it online so that you can easily reload it through the Transport for London (TFL) site and check the balance as you use it. That site can also be used to plan your journey from start to finish using all methods (tube, bus, etc.) of transport offered in London - quite handy!
The security at each train station is akin to that of New York's subway system. To get to the terminals, you have to check-in at one of the many kiosks in the station. Each kiosk has a set of doors that blocks you from entering or leaving the terminal without swiping through with your Oyster card. This way, you can be charged the accurate fare for the distance you rode between both checkpoints.
It would be wise to make sure you have plenty of money on your card prior to checking in because there are very few, if any at all, ticketing kiosks inside the security gates. So, if you check-in at a security gate with only £2 on your Oyster card but the fare for the ride ends up being £2.40, you won't be able to swipe out of the gates to leave at your end destination until you put enough money on your card to pay the fare. And since there aren't many ticket machines inside the gates, you'd have to flag down a tube employee and have them help you - something that will just take unnecessary time.
I've found that the best way to navigate the tube system is by using a London underground map app on my phone. It's the fastest and easiest way to ensure that I am on the right train and headed to the correct destination. And, because I chose not to get international service on my phone while studying abroad, the fact that the app works without any internet connection is even better.