It can be all of those things. The existence is a military policy. The fact that many of them cut through and decimated minority businesses and neighborhoods r

It can be all of those things. The existence is a military policy. The fact that many of them cut through and decimated minority businesses and neighborhoods rather than just solely going around cities in a beltway fashion (as is done in Europe and was Eisenhower's original intention) was an intentional social policy to remove "blighted" areas.