Sharrows are those chevron shapes you see on streets sometimes that indicate that car drivers should be ready for bikes in the lane. It's an explicit direction to cars to share the lane. It's a feature I like, although there is a debatable downside since drivers may assume that the absence of sharrows means bikes should not be present. The most prominent example in my neck of the woods is on Dean Keeton St.
My attention was recently directed to a study (an actual! scientific! study - find it here) showing the benefits of installing sharrows, especially in reducing the risk of one of my greatest fears: dooring. Dooring is when a parallel-parked driver opens their door in front of a biker in the "door zone" who is then forced to choose, in a split second, between attempting to stop, hitting the door, or swerving into the lane (there may or may not be a car there, and there's probably not time to check). It's definitely a great way to get the heart pumping and circulate adrenaline.
The best way to avoid being doored is to ride outside the door zone. If you have to ride to the side, take the lane early when there are parallel-parked cars, and watch for tell-tales on parked cars. Brake lights switching off or interior lights turning on are a good sign that the driver-side door is about to open. I also have a habit of looking in the side-view mirror to see whether there is a person in the driver seat. I never assume that person sees me and slow down or give a wide berth in case the door opens.
When a sharrow is installed, a bike rider can have more confidence riding in the lane outside the door zone, and many of these things are not an issue.
Be safe, ride hard.