Barcelona had magnificent streets: 4 for cars in either direction, 2 for bikes in either direction, and wide pedestrian promenades that are at least 2 lanes wide.
Those magnificent streets are full of cars, scooters, and bikes. Most of those bikes fold so they can be taken on the Metro, store easily in a small apartment, and are inexpensive. I saw all types of folding bikes, including one with an electric motor. The bike lanes have their own lights and even take you safely around the roundabouts.
Out in the country, near Girona, we just rode right up, into, around, and out of the roundabouts on our way to ancient ruins, hills, or the coast.