Which street is 12.2 miles long?
CREATE TABLE "table1_10568553_1" (
  "county" text,
  "location" text,
  "street_names" text,
  "milepost" text,
  "roads_intersected" text,
  "notes" text
);
SELECT "street_names" FROM "table1_10568553_1" WHERE "milepost"='12.2';