Most places are not set up for bikes. Bike lanes are largely an afterthought, placed between traffic and parking, making an accident all but inevitable.
You can basically run over a cyclist and kill them with few to no repercussions, because we just don't have enough safeguards in place to protect cyclists from drivers driving off, never to be heard of again.
The vast majority of the US is not cyclist friendly, it's a hazard.
Edited to add: Here's a simple basic proposition. With curbs each between cars / bikes / pedestrians.