Actually, the cities were mostly WHITE when the Interstate System was designed. And by the way, the reason it could even be funded federally was because it was classified as a national defense priority for evacuating cities in the event of a pending nuclear war (back then, the feds had to actually justify spending money domestically), and because of that purpose, it HAD to go into the cities and the (then) white neighborhoods.
It was not the fault of the designers that the cities turned diverse, nor was it RACISM.
I know the history of Hartford, CT.
When the highways were built they cut through Jewish areas of the city.
Then the blacks rioted and the Jews had to flee for their lives.
Now the highways cut through black areas of the city.
The inner cities were already plenty heavily minority by the 1950s. But the interstates did help the less affluent move to the suburbs AND still work in the cities.