Bicycles have been around for a long time. In the last 5 or 6 years they are widely used in cities as an alternative to the automobile. Bicycles take up less space, produce no pollution, and help keep people fit. Unfortunately there is conflict between bicycle and cars. Many car and truck drives believe bicycles do not belong on the roads and streets. The roads and streets were made for cars and trucks and the bicycles should get out of the way.
Now many cities have bike lanes that help separate vehicular traffic from bike traffic. Still there is nothing to keep a car from veering into the bike lane. To remedy this the city of Denver is installing rubber curbs to separate bike lanes from street lanes. They are easy to install by driving a spike through the rubber curb into the street asphalt. When a car hits one of these curbs it is thrown back into its street lane.
From personal experience open bike lanes did not make me feel particularly safe. First they are too narrow and second a lot of them were outside car parking spaces. All it takes is for a driver to fling open a car door and wham you are down, even flung into the car lane.
Generally, I feel safe riding on roads that have wide shoulders, although there is nothing to keep a bike hater from deliberately swerving into you. One time in Kentucky I had a passenger in a pickup throw a cup of ice at me. I decided not to bicycle on that road any longer. This brings me to another factor in bike riding. Areas of STRESS. Areas in cities have been identified by bicyclers as stress areas. These are areas where bicyclist feel unsafe even when designated for bicycling.
it may take a while for city street departments to catch up with the changing dynamics of city transportation, but it is happening slowly. I wonder how many city street employees bicycle to work.