Yellow Change Intervals

All papers except for two are PDF documents describing the physics of the ITE yellow change interval equation.

The two "Empirical Data" downloads are zip files of Excel spread sheets and graphs. The "Verifying Solution" download contains Excel spread sheets graphing red light violations rate versus time-into-red for various tuples of yellow change interval and traffic lane. The analysis considers 140,000 data points from raw red light camera data from many intersections. The analysis shows that when traffic engineers decrease the yellow light by 1 second, the tail end of curve extends 1 second further into the time into red. The amount of time into red is predictable by the equations of motion defined in the papers.

The other empirical download is the "Yellow Time Affecting" zip file. It contains graphs from over a dozen cities in the USA. These graphs show red light running rate versus yellow change interval. The graphs demonstrate that run red light running is almost solely a function of the duration of the yellow light.

The conclusion is that red light running is not a function of errant driver behavior but rather of the conflict between traffic engineering practice and the laws of physics.

Webinar 1: Physics of the Yellow Change IntervalDownload 
Webinar 2: Misapplications of Physics of the Yellow Change IntervalDownload 
Webinar 3: Engineering Malpractice: Yellow Lights, Red-Light Cameras and JurisprudenceDownload 
Yellow Change and All-Red Clearance SolutionDownload 
Traffic Technology International Cover Story - Red Light Cameras Exploit Bad Physics of Yellow Light EquationDownload 
Derivation of the Yellow Change Interval FormulaDownload 
4 Problems with the ITE EquationDownload 
Misapplied Physics in the Yellow Change IntervalDownload 
Empirical Data Verifying Yellow Change and Red Clearance SolutionDownload 
Empircal Data Showing Yellow Time Affecting Red Light Running RatesDownload 
The Problem of the Amber Signal Light in Traffic FlowDownload 
Determination of Left Turn Yellow Change and Red Clearance IntervalsDownload 
Dilemma Zone Driver Behavior as a Function of Vehicle Type, Time of Day and PlatooningDownload 
Total Files13
Create DateDecember 29, 2015
Last UpdatedJanuary 5, 2020