Pedestrians: they have no rights on major crosswalks. If a pedestrian is ahead of you, and steps into the road, drive on, speed up, honk, or yell loudly and chase him back up on the curb. Never, ever stop for a pedestrian unless he flings himself under the wheels of your car.
Drivers: the first parking space you see will be the last parking space. Grab it! No matter what.
When it comes to Berlin's public system, it does have the best subway, train, and bus transportation. I even tend to say worldwide. It's working almost 24,7. Most of the stations are meanwhile very friendly for disabled ppl. One can live in Berlin year after year without missing any vehicle ever. Stick with your cycle or public transportation! Now, who are the thousand of drivers that never use directional signals when changing lanes, thinking they only would warn other drivers to speed up and let no one in?
Be careful not to step into the street while taking in the sites, or getting your picture taken. Vehicle traffic does come through that street and it appears they are not tolerant of tourists standing in the road. Why should they be? Many tourists ignore the vehicles and back up the traffic. Watch out for the vehicles and be respective they need to get to their destination.
When you see the pink paving along side the normal walking cobbles, know that it is the bike path! Do not walk on the bike path if you can help it! It's just for bikes of course. :-) If you happen to be on it and here a bell ring, don't run or move especially if the sound was close! Someone on a fast moving bike is just about to pass or hit you! As a friend described to me, "If you hear the bell, prepare for impact!"
Berlin bicyclers can get up to tremendous speed, and follow the traffic signals for cars also. In main street traffic, this is not so difficult to understand, because they have to stop and let you cross just like cars and buses do, but on neighborhood streets for example, one has to really watch for bicyclers. They have the right of way just like cars. Look before you cross the street, just because you don't see or hear a car, doesn't mean you can go. You need to stop for bikers as well and let them pass.
Again be aware of your placement when stopping at corners, walking along, etc. its an interactive thing. Bicyclers are trusting you to keep your path, and stay clear of their designated area. If you do get into a situation where another person is blocking your way to get off a bike path, or a bicycler is having to circumnavigate others, its best to keep your place. Stay still, and let the biker go around you, than you trying to jump out of the way. More likely you will cause an accident that way.
I walked back to Tiergarten. A road and transport incident happened with me. Walking across Berlin, it is necessary to watch attentively not to appear unintentionally on a bicycle path which is marked on sidewalk by red color. I have already got used to it, and went legislatively on foot sidewalk when unexpectedly behind the boy was cut into me on a bicycle. Both of us have fallen, and I was put painfully enough. The boy was hurt too, but he was not upset at all, and did not think to apologize. Then I had to state emotionally, what I think of his manner of driving on a bicycle.
I thought Copenhagen had mad cyclists but at least they cycle on designated paths for most of the time. Berliners are experts at cycling on the pavements just about everywhere, including in shopping malls. I found it highly annoying.
Even in relatively cold (but not freezing) February I found quite many bicycles in use around Berlin. Those of them parked on a street were always locked by bicycle lock.
Follow the locals... if you want. Maybe they know better what to do to avoid problems. Personally, I think it's not necessary to lock the bicycle in this area of Berlin I visited (downtowns/centres) but... just in case. When you rent a bicycle you may ask about insurance against thefts.
Before you enter downtown/center of Berlin by your car:
1. check whether you have enough fuel/gas - there were no gas/petrol stations in the centre or I didn't see them; never mind, better not to lose time for looking for them;
2. check your destination (district, street name) and mark your itinerary on the Berlin map necessarily with one-way streets marked (there were few in Berlin :-); altrnatively you can check your itinerary on GPS map while driving if your car is equipped with GPS system, mine wasn't :-( ;
3. have change ready - coins 2 €, 1 €, and/or 0.5 €, street parking meters needed them :-). Parking garages were much more expensive but if no way...
Since the fall of the wall in 1989 you are no longer allowed to drive your armoured personnel on the Autobahn! I guess these road signs were left over from when west Berlin was occupied by American, British and French armed forces.
When riding a bike... make sure to look out for the S-bahn tracks. My front tire got caught in the track in Potsdam, and when I turned my wheel, I flew over my handle bars. I can say, with much pride, that I didn't cry and the guys were all very impressed. They decided I should get some photographic evidence once we got on the train to go home. Don't let this happen to you!
There is a lot of police in Berlin. So take care when driving with your car.
Take care when parking your car. Although Germany is known as a secure country, you can expect that your car can be scratched by drunkards at night or your radio can be stolen at night. So be sure where to park your car and don't feel too secure! Be cautious!