the Green Line

An imaginary line down Alter Rd, a border between Detroit and an affluent suburb, Grosse Pointe. Driving across the Green Line is obvious and somewhat striking, as the surroundings turn from abandoned buildings and brown lots to mansions with green grass and trees, hence the Green Line. It can even be seen on satellite images from Google Earth. The green line is also reportedly the largest difference in average house value across a single street anywhere in the world.