Part 1: 1994 TRB distinguished lecture. Part 2: Traffic flow and capacity. A peer-reviewed publication of the Transportation Research Board TRB.

Part 1: In 1990 the Transportation Research Board Executive Committee approved the establishment of the Distinguished Lectureship Series to recognize the career contribution and achievements of an individual in one of four areas covered by the Board's Technical Activities Division: transportation systems planning and administration (Group 1); design and construction of transportation facilities (Group 2); operation, safety, and maintenance of transportation facilities (Group 3); and legal resources (Group 4). Part 2: The 25 papers in this volume are related by their focus on highway capacity, quality of service, traffic flow measurement, and traffic flow theory. However, the papers cover a wide range of problems reflecting the concerns of practitioners als wel as theoreticans.