Have any cities made dedicated bike roads?

It’s really dangerous to ride a bike on the roads in my 3rd world city even walking is dangerous due to bike lanes basically being ignored, motorcycles weaving around traffic, and poor nighttime lighting.

I just thought that dedicated bike/walking only roads connecting the major parts of my city would be a big boost for safety and I think it would greatly reduce the amount of people using cars.

Has this been tried somewhere else? Was it successful?