A biker was sidewalk biking at around 10-15MPH on the opposite side of the street from me when I made a legal (signaled) left turn into a driveway on the other side of the street and hit him, and didn't see him because there was heavy rain. I was going around 5-10MPH when he was hit, and he did not fall of his bike or get injured. He is taking his bike into a shop for repairs. Am I responsible for damages, or is he?
Unfortunately, you are responsible for making an unsafe left turn. The law requires that in making a left turn that you are responsible for making that turn only when it is safe to do so.
