SPECIAL TRANSPORTATION SCIENCE ISSUE.

In the twelve articles that are included in this January 1964 issue of "Operations Research," the largest number deal with delays and congestion characteristics of four-arm intersections, merging intersections, vehicular-controlled intersections, and the control of a sequence of synchronized signals. The remaining papers include the results of bus-following experiments, the flow reduction aspects of removing arcs in a transportation network, the economic justification for establishing runway service priorities in an air traffic control system, the mathematical characteristics of two traffic systems whose service times increase with their occupancy, and the distribution of certain measures of travel in a circular city. publication needs of authors actively engaged in the field. This publication recommendation was adopted by the Publications Committee under its chairman, Robert Machol, and an Editorial Committee was established to handle the special issue under the chairmanship of Robert M. Oliver, who also served as editor for this special issue.