Donald Appleyard

Donald Sidney Appleyard (July 26, 1928 to September 23, 1982) was an English American urban designer and theorist who taught at the University of California, Berkeley. He is known for research demonstrating the relationship between vehicle traffic volume and neighborhood social life; his 1981 book Livable Streets compared three San Francisco streets carrying between 2,000 and 16,000 vehicles daily and found that residents on the low traffic street had roughly twice as many acquaintances as residents on the high traffic street, establishing him as a pioneer in understanding how street design and traffic intensity affect community cohesion and urban livability.