Transportation in Berlin
It's best not to think of Berlin's train and underground rail networks as independent of each other, because they're so seamlessly integrated. Operating from 4am to past midnight, there are 15 S-Bahn and nine U-Bahn lines. Maps of the system are readily available and display the network as a simple whole. The S-Bahn and U-Bahn run 24 hours on Fridays and Saturdays.
In addition to the rail network is the bus system. Buses are not as quick, but at least they're comfortable. After midnight they can be your only option. Tickets are sold on board and stops are marked with an ‘H'. Bus routes 100 and 200 take in Berlin's key landmarks and are a cheap, fun way of seeing the sights; both stop at Unter den Linden.
Rent your car
Wide tree-lined avenues and main sights that are easily accessible by road make Berlin one of Europe’s most drivable cities. Only low-emissions vehicles are allowed into central Berlin - so make sure your hire car has a special Green Zone sticker. Remember that cyclists have right of way on the city's many cycle routes.
Ticketing on Berlin's various public transport services is fully integrated, which means you can use the same ticket on S-Bahn, U-Bahn, bus and boat services. The best option is to buy a Tageskarte (day ticket) which can be used on all transport systems for a whole day (until 3am the next morning). A ticket covering zones A and B should suffice to cover the main tourist sights. These can be bought from the ticket machines on S-Bahn and U-Bahn platforms. Single tickets must be stamped before boarding. Don't even chance not buying a ticket as ticket inspectors don't wear uniforms and are very difficult to avoid. The Welcomecard is ideal for visitors - valid for 2, 3 or 5 days it gives the holder unlimited free travel as well as discounts and free entry to some sights.