KCBS has opted not to renew the contract of veteran local air traffic reporter Bob Tur when it expires Sept. 30.In Tur’s place, the station has enlisted Metro Traffic, a longtime radio traffic service that will be making its maiden push into TV news via KCBS. It’s believed that the move is a cost-cutting step, with the new reporting system supported primarily by advertising and barter. Tur has won more than 30 major awards for journalism including the Edward R. Murrow Award, the George Foster Peabody Award and an Emmy. It was Tur and his wife, Marika, who shot the videotape of the riot attack on Reginald Denny at the corner of Florence and Normandie in 1992. Tur’s was also the first chopper over the O.J. Simpson-Al Cowlings Bronco pursuit.