Bicycle accidents result from various factors, which can include poor weather conditions, defective bike parts, potholes, etc. But the majority of bike accidents occur due to some kind of negligent act, such as the following, either by another driver or bicyclist:
Distracted driving
Pulling out of the intersection in front of a bicycle or vehicle
Ignoring the stop sign or running the red light
Driving while under the influence of alcohol and/or drugs
Passing on the right
Not yielding at an intersection
Driving (drivers) or not driving (bicyclists) in a bike lane
Riding in the blind spot of another vehicle and not checking for potential blind spots when switching lanes