Urban cycling is not as safe as it should be. Stories like these are common:
This is a good guide to safe cycling that I recommend: the "ten ways to not get hit by cars".
There are many tips that I already knew from my experience as a cyclist and from recommendations from the authorities and friends.
What I have discovered reading this guide is that there are many places where bikes are not respected at all. Look at this example:
In every tip it is said that cyclists must ride on the left side of the lane so that motorists can see you. And they recommend not to be worried about cars if they can't pass you easily. I can confirm this. Please, do it. When I haven't done it thinking "oh, poor car, they will want to go faster to somewhere" I've felt like I was going to be knocked down. Drivers may complay if you don't do it but don't care. They will have to wait at traffic lights anyway.
Other problems are crossing sidewalks, and it is true. Once, I was hit by a car in the way they mention. The driver was just looking in the opposite direction I was coming. Luckily, I had already noticed that and I had slowed down. Nevertheless, I thought the driver had seen me and I started to cross without stopping completely. He hadn't and I was hit by him. Don't worry, I just fell off my bike!
Ultimately, riding a bike is sometimes really dangeours and you must be extremely cautious if you want to arrive safely.