United States Bureau of Public Roads Pennsylvania Department of Highways 27 New York (State) Department of Public Works 22 United States Federal Highway Administration 22 Massachusetts Department of Public Works 19 United States Public Roads Administration 18 New York (State) Dept. of Public Works 17 Wilbur Smith and Associates 16 Louisiana Department of Highways 10 California Division of Highways 9 New Hampshire Department of Public Works and Highways 9 Automotive Safety Foundation 7 Connecticut State Highway Department 7 H.W. Lochner and Company 7 Illinois Division of Highways 7 Stanford Research Institute 7 Wisconsin State Highway Commission 7 Dansereau, H. Kirk (Harry Kirk), 1921- 6 Levin, David R (David Richard), 1913- 6 Liston, Laurence L 6 Minnesota Department of Highways 6 Pennsylvania State University Institute for Research on Land and Water Resources 6 United States Federal Highway Administration. Office of Highway Information Management 6 United States National Park Service 6 United States Office of Highway Planning 6 United States Office of Highway Safety 6 Charles A. Maguire and Associates 5 Edwards and Kelcey, Inc 5 Louisiana Dept. of Highways 5 Maiolo, John R., 1938- 5 voir tous les ...