This story, from WBEZ 91.5 in Chicago, offers the most thorough, easiest-to-understand explanation of federal traffic lighting and control standards I've ever heard.
In June 2017, Manual on Uniform Traffic Control Devices Section 4D.26 rules for determining yellow and red light intervals change to "engineering practices" -- specifically, the Institute of Transportation Engineers' (ITE) kinematic equation (the formula's in the article).
Were Chicago engineers encouraged to stick to the "old" yellow-light formula to fill city coffers? As a Chicago driver who's traveled this intersection, I understand why the young man in this article (as well as these survey respondents) think so. Or, in a city where two to three cars routinely complete left turns after the light's turned red, is sticking to the old formula a way to save drivers from themselves?
What do you think? Comment below or e-mail firstname.lastname@example.org.