Originally Posted by
Zedoo
As bikes, rickshaws, horses, etc. replace cars and traffic volume decreases, basic wide roads can simply be narrowed and the unused lanes become front yard. How will divided roads be narrowed? With medians 20-60 feet wide, making one side the entire road will make some awkward real estate. A new road surface could be laid in the median, but I don't see the state, county, or city governments of the future having the money to do that. I frequently ride a divided road, with 4 lanes each way and the median, for a total of 180 feet wide.
I don't think you'd see more boulevards in the scenario you describe. You'd probably see bicycle and pedestrian infrastructure squeezed into existing streets. In highly populated commercial areas, you might see some sidewalk cafes creep out a little, but in residential areas you'd probably see less lawn and more "in-fill" development.