I-74 with 2 Mahomet exits. I dunno if that was explicitly racism, but a load of money was made developing real estate. Well, yes, part of it was racism. They really did not even try very hard to hide it back in the day.
The more explicit racism was that freeways were specifically routed through areas that didn't have the political clout to keep their neighborhoods from being plowed over and split, and then have emissions and noise as part of the bargain.
When they wanted to build 580 and 980 through Oakland, they just did it. When they wanted to run x80 through Golden Gate Park in SF, the citizens said no way and the project died. The only added freeways that happened were the freeway extension of US-101 and I-280. Then when Hayes Valley started to gentrify, they tore down the Central Freeway, and after the earthquake they tore down the Embarcadero Freeway to set up the refurb of the ferry building serving Marin commuters.