August, 2017 Luncheon

Speaker: Brian Ceccarelli, Talus Software

Date: Thursday, August 17, 2017

Topic: The Yellow Change Interval – Physics in Opposition

Summary: This presentation starts with William Potts, the Detroit police officer who invented the yellow traffic signal light in 1920, then moves on to Alexei Maradudin, the University of California physicist who invented the equation traffic engineers use today to set the duration of the yellow light. Engineers have been using his equation since 1965, applying it universally to all types of traffic motion approaching an intersection. But Maradudin’s equation accommodates the kinetics of only one case of traffic movement. The equation conflicts with the kinetics of the rest. By traffic engineers applying his equation universally, the engineers induce a systematic failure into every traffic signal, a failure causing reasonably-perceptive drivers to unwillingly run red lights. The driver experiences this failure by either stepping on the gas, by slamming on the brakes or by consigning himself to run a red light, the latter option occurring frequently when decelerating for turning and avoidance maneuvers. The failure does cause crashes. The presentation concludes with a word about the compatibility between engineering, physics and man-made laws.

Brian Ceccarelli is a licensed professional engineer (software engineering) in the State of North Carolina. Mr. Ceccarelli current owns his own company and works on various software projects. Mr. Ceccarelli has designed and built applications for NASA’s Mars Observer spacecraft, applications for calculating stresses in copper mines in the Congo and Chile, and CAD/CAM applications for the US defense industry. Ceccarelli took an interest in transportation engineering when the Town of Cary, North Carolina bestowed upon him a red light camera ticket. Mr. Ceccarelli since has been published in Traffic Technology International, has been an expert panelist in traffic signal timing for the Institute of Transportation Engineers 2015 International Convention, and a speaker at the International Autonomous Vehicles Symposium in Stuttgart, Germany. Mr. Ceccarelli has a B.Sc. in physics and is a member of ASCE, ITE, and IEEE.

ASCE NC Web DirectorAugust 22, 2017