city blocks for my buildings

I am having trouble making a city blocks for my buildings in a city. I need to make the blocks big enough for my buildings, but having trouble making the street small enough so that the street to not look so big in comparison to my buildings. I need streets with a white line in the middle and back on both sides of the white stripe. What is the best way to make a city scape block, I have about 10 or so buildings.