A street in Oakland recently underwent a road diet: two of five lanes were converted into protected bike lanes. The result is an increase in biking and pedestrian use, a decrease in collisions, a decrease in speeding, and an increase in business along the street.
Road dieting seems to be happening a reasonable amount in London at the moment, particularly around the improved Cycle Superhighways.
Braess’ paradox or Braess’s paradox is a proposed explanation for a seeming improvement to a road network being able to impede traffic through it. It was discovered in 1968 by mathematician Dietrich Braess, who noticed that adding a road to a congested road traffic network could increase overall journey time, and it has been used to explain instances of improved traffic flow when existing major roads are closed.