That might have been true but it wasn't THE reason for the Conncourse. The seperation of transportation systems was brought to OKC by IM Pei (a follower of Le Corbusier).
1) Elevated freeway traffic
2) One way high capacity city streets
3) Pedestrians underground, in internal cooridors, and on skywalks.
All 3 made OKC what it was in 1992. 2 of 3 have since been corrected.