In Memoriam: Professor Emeritus Adolf D. May

Dr. Adolf D. May, Professor Emeritus of Civil & Environmental Engineering, passed away on August 16, 2023. He was 96 years old.

Professor May pioneered the science of Highway Transportation in Civil Engineering, creating and receiving the first Ph.D. in the field in 1952 at Purdue University. May was passionate about his work as a researcher and educator, retiring from UC Berkeley after nearly four decades of service. 

Before teaching at Cal, May taught at Clarkson University, Michigan State, and Northwestern during his early career. His career included working for a consulting firm and as the Assistant Secretary for the Institute of Traffic Engineers. He was a leader in the areas of highway capacity and quality of service and the development of prototype driver models for highway design.

May was perhaps best known for his work in designing and managing highways, rural roads, and signalized urban streets. His 1967 research study "Simulation Study of Load Factor at Signalized Intersections," published in Traffic Engineering magazine, created a sensation and resulted, 18 years later, in using delay as the level of service criterion for signalized intersections. In 2018 the East Bay Times featured an article titled, "Dolf May: Traffic World Legend Who Invented Metering Lights”, which continues to be used in many parts of the country to this day. He also developed freeway control systems, starting with his early work in computer systems as the first Director of the Chicago Area Expressway Surveillance Project in 1962.

In 1990, May was elected to the National Academy of Engineering, the highest professional honor for an American engineer. He was recognized for the quality of his work in traffic engineering and theory. Out of the 1,000 engineers then elected to this office, May was one of fewer than 20 who practiced transportation engineering. He also received the Theodore M. Matson Award in 1992, the Transportation Research Board's Distinguished Lectureship in 1994, and a Caltrans 1987 Award for Excellence in Research. 

A memorial service will be held for him in Santa Barbara, where he and his wife Margaret retired. See his obituary for more about his life and the upcoming service on September 5th.