Santiago, Chile did this in the last 10 years. They created a separate bidirectional bike lane, often separated from
vehicular traffic by a small cement barrier (a cub basically) on key routes. You really don't need this on every road, just some routes. When I used the bike option in Google maps, it was super easy to ride around the city.
Suburban areas are different and Randy Scott sounds whiny in his post. It's not hard to drive around cyclists; and it's not hard to pick a bike route that avoids narrow roads without bike lanes.