Hearings before the subcommittee on investigations and oversight of the committee on public works; House of Representatives; 92nd Congress, 2nd Session, Washington, D.C., April 11-13 and June 20-22, 1972.

Traffic operational hazards are discussed. The point of convergence, the place where all the planning, and designing, and engineering come together is outlined. Four lectures with a lot of photographs which shown these hazards are given.