RULE 1
Don't get yourself killed.
Nobody follows any rules in San Francisco. Cars don't stop at stop signs. Drivers talk on their cell phones. Bikes don't stop at red lights. Pedestrians randomly step out into traffic without looking. Always bike assuming that someone else is gonna crash into you doing something stupid. Anticipate others breaking the rules and you'll stay safe. Ride where you can be seen. Ride where the cars aren't. Ride on streets with bike paths. Ride on streets that suck to drive on so the cars are going slower. Look for ways to escape from dangerous situations. Watch out for cab doors opening into you. If there's a crazy maneuver that will keep you from getting crushed or hit, do it. Run that stop sign to get away from the swerving SUV looking for a parking spot. Cars can't see you when you hang out in their blind spots, so don't do it. If someone doesn't know you're there and is in the process of killing you, yell at them (then be nice afterwards).
RULE 2
Don't get anyone else killed.
Regardless of who is breaking the rules, don't get anybody killed. If you're illegally on the sidewalk trying not to get killed on the road for some reason, ride really slow and be super nice to people walking. Use your bell to let people know you are coming. Don't smash into j-walkers just because it's your turn and you're faster than them. Don't cause car accidents even though you have the right away. A good general rule is that anyone smaller than you has the right away.
RULE 3
Be nice.
There's enough tension between cars and people as it is, don't make it worse! I try and time 4-way stop signs so I never make anyone else wait for me. A good trick I use is to approach the intersection being highly aware of all cars, and then ride on a car's coattail through. This allows my momentum to get me through the intersection quickly without making any cars wait for me. Ride so you aren't in the way of the cars. Say hello, excuse me, and sorry to everyone. Being nice is part of the San Francisco culture. If you're super friendly, you'll fit right in.
RULE 4
Have fun.
Ride in a way that makes sense for you on a bike in terms of stop signs, traffic lights, and road signs. Rules of the road were written for cars and then applied with little thought to the needs of bikers. Most car rules feel more like suggestions when you're on a bike. Usually, it's more fun to ride in the bike lane but sometimes it's not, so do what makes you smile. You are also legally allowed full use of the road here in California. Cars have to yield to bikers, so don't be scared of them! Go between the cars and get to the front of the line at red lights. They can see you better if you're in front of them anyway.
RULE 5
Follow the traffic laws.
Although culturally it doesn't seem like anyone follows any rules sometimes, legally you are supposed to follow the same rules as a car driver would. That means you can get a ticket for riding a bike the way most people ride bikes around San Francisco. Until the day when riding a bike is covered by more sensible traffic laws, we are legally forced to take car laws as the law of the land. Don't get a ticket by breaking laws.
AND LASTLY
Lock up your bike really really well when you leave it anywhere, and always have front and rear bike lights with you for night time so you're visible. Follow these rules and you'll fit right in here in San Francisco. The crazy bikes who break all traffic laws have created a culture where car drivers here are scared of bikes. This will work in your favor if you ride nicely and stay out of people's way when possible. Riding a bike is the best way to explore San Francisco and the more bikes on the road the safer it is for the rest of us. Please come see our city by bike. We would love to have you.
