Introduction
Copenhagen's public transportation system consists of three major components, S-Tog (S-Trains), busses and the latest addition, the metro. The entire system serves most of the eastern parts of Sjælland (Zealand) including the small island Amager where Copenhagen's major airport, Kastrup, is located. The bus lines extends the furthest out, with lines crisscrossing the urban areas, but getting thinner near the northern and western areas. If you want to go further west you can take a regional bus service or use the railroads which covers most of Denmark.
Getting a ticket
First problem you will have to face before using public transportation in Copenhagen is getting a ticket.
Tickets can be obtained from three major sources. If you go by bus, the bus driver will be able to sell you a ticket, as long as you have almost even money. Bus drivers are not allowed nor even able to give you change on large bills, because for security reasons they are not allowed to drive around with large amounts of cash.
If traveling by train, either the S-Trains or metro, you can buy a ticket from one of the automatic ticket machines which are placed in every station. The metro stations feature high tech touchscreen systems. The S-Train stations have conventional but still fairly slick pushbutton systems. The automatic machines take all Danish coinage and can pay you back change on any amount of cash you insert. Machines on the metro also take major credit cards.
Lastly, each train station has a ticket office, but these are only open during daytime. On the bus or at the ticket office you will have to make yourself understandable to the driver or the clerk. If you are from Denmark, you will already know the first language of the ticket clerk and a language barrier will not be a problem. If you don't know how to speak Danish, then worry not (not yet anyway), because chances are your average Dane (that includes ticket clerks and even bus drivers), will be able to not only understand, but quite likely also speak English semi-perfectly. Now if you don't speak English, most of the time German will also be acceptable, however occasionally you will run into someone who won't understand a word. If you have a clerk that for some reason don't understand a word of what you are saying, you may still be fine as long as you in some way can convey your intention as to how many zones you need to travel. Handsigns may work.
The whole area covered by the Copenhagen public transportation system is divided into roughly squarish subareas called zones. Maps with the zones painted on in friendly colours are positioned strategically on train stations and bus signs. Basically you need to find out which zone you are in currently, and to which zone you need to get off. The ticket price depends on how many zones there are from where you are now to where you want to go. You must count both the starting and ending zones. Also as a special rule, you have to buy a ticket for a minimum of two zones, even if you don't need to leave the zone you are in!
The way the system really works is that when you get your ticket, the ticket will have printed the zone where you bought it, plus the number of zones to your destination. With your ticket you are actually totally free to go in any direction you choose and travel as much as you like within the circular area of zones that extends outward from your starting point to the radius of the amount of zones you paid for. This is until the ticket expires. When your ticket expires, depends on how many zones you bought.
Getting around
The fastest way to get where you want to go is to hop on the S-Train. In many cases it will pay off well, to actually go in the opposite direction of where you want to go, just to catch the S-Train and travel to the station which is nearest to your destination and then take the bus or walk from there. This trick doesn't even seem to be widely known among regular commuters in Copenhagen.
The S-Trains run in a spider web fashion, with a circle line running through the outskirts of Copenhagen from the bridge quarters Østerbro and Nørrebro and ending in the western part of the city called Vanløse. The wires of the web go out from the central station Hovedbanegården with two lines going north towards Klampenborg and Hillerød. Two going northwest towards Farum and Frederikssund. One going west towards Høje Taastrup. And lastly one going south towards Køge. The line towards Klampenborg is actually an extension of the circle line and doesn't start at Hovedbanegården. The circle line actually only goes halfway around the system. It stops at the line that goes out towards Frederikssund, on the new station Flintholm which was opened along with the metro. An extension to complete the circle is currently under completion.
To get on the S-Train, first get your ticket. Tickets are not sold on the train, so you have to use one of the above means. When you have your ticket, go to the platform and wait for your train to come. When the train comes, wait till it stops and makes some beeping sounds. This is the sign that the doors have been unlocked and can be opened. The doors are opened on older trains by pushing the vertical door handles sideways. On the new models you press a button on the door with green lights embedded. When you want to get off, use the exact same procedure from the inside of the train. Trains always stops at all scheduled stations and never stop at unscheduled ones. Have a look at the maps on the station to find out where the scheduled stops are. If you get on the wrong train or go past your stop, please don't pull the emergency brake or some other crazy stunt like that. Just wait until the train stops at its next scheduled stop and switch to a train going back to where you came.
After the S-Trains, the second most useful means of public transportation in Copenhagen is the metro. Compared to the S-Trains it only covers a very small area, but at least it is fast. The metro was opened in 2003 and at the time of writing is still very much the 'new thing' to try in Copenhagen. Despite being widely criticised in the Danish media for being overly expensive and having just a bit too many startup hiccups, it actually runs like a breeze most of the time, and the well lit modern stations and cormfortable trains are a fairly enjoyable experience. The two lines goes from Vanløse station through the city and then splits up with one line going along northern Amager and another going through the new quarter of Copenhagen, which is currently being developed, Ørestaden.
When traveling by metro again you need to buy your ticket beforehand, like with S-Trains. Actually getting on the train amounts to nothing more than waiting for the train to stop, the doors to open, and bording the train. All mechanical aspects are automated. The trains are driverless and you can actually step right up to the front window and look out at the tunnel zipping by. Quite a lot of fun. When you want to get off, you simply wait for the train to stop and the doors to automatically open, and then step out on the platform.
Lastly if you can't use any of the above, the busses are probably preferable to walking, especially in the suburbs where the stops are a longer between and the traffic passes faster. As mentioned above the driver sells tickets so all you have to do is get on the bus. The way to get on the bus may be different from what you are used to in your country. The bus basically stops if there are any people waiting at its scheduled stop. You don't need to signal with your hand your intention of wanting to get on the bus. The bus driver should stop if there is even a remote possibility that you want to get on. City busses never stops between scheduled stops, no matter how much you wave your hands or in other ways signal that you want to get on. Always board the bus through the front doors, never the middle or the back door. Those are only for people stepping out of the bus. If you have already bought a ticket, be sure to show it to the bus driver, and don't go past him until he gives you a friendly nod. Sometimes if many people are on the bus, the driver may be fairly indifferent to checking peoples tickets, so if the driver just stares out in the air, just hurry on down the corridor. If you don't have a ticket, now is the time to buy one.
When getting off, you have to press one of the stop buttons on the bus. This sounds a bell on the bus and a red stop signal in the front end of the bus under the roof will light up, so everybody can see that the bus will stop at it's next stop. A telltale will also light up in the bus drivers control panel, reminding him that people want to get off. If you don't press stop, and there are no people to pick up at the scheduled stop, the bus driver is free to pass on to the next one without stopping. Even if there are people to pick up, he might not open the rear doors if nobody has pressed the stop button, so do press it if you are getting off. The right time to press the button is just after the bus leaves the stop just before the one where you are getting off. You should wait just long enough after the stop, so there is no doubt you didn't want to get off at the stop you just left. You really need to know the correct stop you need to get off at, or you will have to use your legs unnecessarily.
Advanced usage
When you get the hang of it, you will probably want to get a rebate card to save a bit of money on tickets. Cards are available in a few obscure variations for people with weird needs, but most people will want to get a regular ten trip rebate card. Rebate cards are avaiable from the automatic ticket machines, from ticket offices, station kiosks (called DSB Kiosk) and selected stores, kiosks and gas stations near major bus routes. For the last three there is a sign near the door you can look for, otherwise just ask the store clerk.
The cards come in different colours depending on how many zones each stamping is good for. The cheapest are the blue and yellow cards, for either two or three zones per stamping respectively. To use the card find one of the charactistic yellow stamping machines and insert the card. On train stations the card is inserted horizontally with the front side up. In busses the card is inserted vertically with the front side towards you. The machine stamps the card with a time stamp, and the zone you are in. Do check that the stamping is correct before you travel. If it isn't, contact either the bus driver or the closest ticket office if possible. If for whatever reason you can't get to a ticket clerk, just go on the train anyway, but do make good note of the the station name and the position of the stamping machine on the station, in case you run into a ticket officer.
If you are at a point where you will be using the public transportation system on a daily basis, you should consider getting a commuter card which is good for one month at a time for an unlimited amount of trips at any time of the day in the zones you buy access to.
If you are going by bus, make note of the special S-Bus lines. They are meant to connect the S-Train stations between the outer wires. Generally they have far fewer stops and travel on more spacious roads, compared to the ordinary bus line, and it makes them faster to travel by. Notice them by the S in front of the line number, and the blue white stripes all the way around the bus, above the windows. There are also A-Bus lines which mostly runs in and out of the city, contrary to the S-lines which mostly runs around it, but has a similar concept of fewer stops.
Caveats
The whole public transportation system is shut down between about one'o'clock a.m. to five'o'clock in the morning.
The last trips mostly does not run all the way to the end points, so watch out for that. For example the S-Trains all stop at the central station on the last trip and doesn't continue onwards to their end stations. After midnight the service is dodgy at best, and you shouldn't count on anything running according to regular shedules.
There are special night bus lines you can take when the regular system is shut down for the night. The night busses only run a few routes and it is quite possible it doesn't stop anywhere near where you are going. Also using the night busses costs twice the number of zones the trip would regularly cost at daytime.
On friday and saturday night, you can also use the metro. It runs with reduced service however, and you may have to wait a bit. The night fees apply as with the night busses.
Don't travel without a ticket. Although there is no check at train stations, you will run into ticket officers on the train just regularly enough that you wouldn't want be caught without one. The fine for traveling without a ticket is 500 DKK.
The delicacies of the zones system occasionally leads to a couple of weird situations. Sometimes when going by S-Train, you will find that it is actually cheaper to go in one direction than it is to go in the opposite. The reason for this is that going by train you sometime have to go further out during the trip than your destination station is counting the distance in zones.
Let me see if I can illustrate this:
__. Starting station
/
\______________. Ending station
Remembering the radial travel rule we see that the turn in your route lies within the circular area stretching out from the start to the end point, making this the cheap way to go.
__. Ending station
/
\______________. Starting station
Now the situation is different. Stations on the turn can be outside the radius of the zone which is you destination. Since you might as well get off at those stations instead of your intended destination, you have to pay for the possibility that you might get off. Stupid? Well that's how it works in any case. There is a way around this situation. If you switch to the circle line, it is possible to get to your destination without going outside the zones you bought ticket for. This means you get the inconvinience of having to switch trains at least twice, but more likely three times, and further having your travel time doubled, which is why most people will just pay for the extra zone they need to travel through.
Bus lines to avoid:
- 18 - Especially during rush hour traffic. If you are in good shape, you will probably be able to overtake the bus walking.
Final notes
A note on safety. Denmark is a very safe place to travel in. Copenhagen is one of the safest cities in the world and this also goes for the public transportation. The risk of being mugged is virtually nonexistant, so don't be afraid to use the public transportation system at any time of the day.