Public Roads Chief gropes for answers. Washington, D.C., Feb. 24. Thomas H. McDonald, Chief of the Bureau of Public Roads, Department of Agriculture, seemed to grope for the answers to questions asked him today by the Senate Banking and Currency Subcommittee. First witness before the committee bearing on the Bulkley Bill providing for $6,000,000,000 system of superhighways in the U.S., financed by tolls, McDonald declared that toll systems had proved unsuccessful as a means of financing European superhighways. At the same time, he said: "Because of different conditions there is nothing to indicate that a toll system would not be successful here," 22438