Red Light Robber

Violations vs Time Graphs

From California, Florida, North Carolina and Virginia, these graphs show how changing the yellow light duration changes the number of red light runners. These graphs were plotted from raw red light camera data. As you can see, once an engineer lengthens the yellow light duration, the number of red light runners decreases--overnight. In the Cary, NC graphs, you see how both the lengthening and shortening of yellow light durations result in decreases and increases, respectively, in red light running.

Not once in the history of traffic engineering has lengthening the yellow light increased red light running. Instead we always see drivers cut short by the federal yellow standard, a standard that opposes physics. It is the traffic engineers' errors and omissions in physics which cause the vast majority of red light running and crashes. The red light data shows that over 90% of red light running and crashes originates from these errors and omissions.

The Yellow Change Interval: Five Major Engineering Errors and Omissions

Every State and Canadian Province imposes a legal requirement on the engineer to "possess the knowledge of the physical and mathematical sciences, and apply that knowledge to their creative work in order to protect the life, health and welfare of the public." This paper shows how traffic engineers misapply the physical and mathematical sciences to the duration of the yellow light thus putting the life, health and welfare of the public in harm's way.

10 Questions for a Traffic Engineer

How well does the traffic engineer understand the ITE formula? Ask a traffic engineer to take the test. Ask a city council to administer this test to its traffic engineering staff. Ask the news media to incorporate these questions into an interview with a traffic engineer. These questions are fundamental to the cause of red light running, and reveal the credibility of the traffic engineer.

Here is the key.

ABET Requirements for a Civil Engineer

ABET = Accreditation Board for Engineering and Technology

NCEES = National Council of Examiners of Engineers and Surveyors

In order to be a licensed professional engineer, NCEES requires that the engineer must know calculus-based physics and know how to compute uncertainties (a.k.a, tolerances, range of error). See page 16.

Board of Engineers Complaint

Traffic engineers are licensed professional engineers and as such must meet legal requirements. You will find the statutes of your State require the engineer to "possess the knowledge of the mathematical and physical sciences in order to safeguard life, health and property." This is the statute the engineers break. Your Board of Engineers can discern it and has the authority to discipline traffic engineers so that they do not do it again. If engineers complied with this statute, then the red light camera industry would not exist.

A policeman, lawyer, judge or politician may be able to discern some of these problems, but from experience he will not speak out against an engineering problem regardless how obvious. He will not speak out for reasons financial, political or because he feels unworthy of making a decision outside his expertise. For this reason the Board of Engineers become essential. The Board should be a person's first stop to seek relief.

We have posted the complaint and cover letter in PDF and Word forms. This is an example of a North Carolina complaint. The checked items in the complaint are the ethics, mathematical and physical sciences violations committed collectively by North Carolina traffic engineers. (The proof for all these violations are at this web site.) Engineers of other states and provinces commit roughly the same mistakes.

A complaint to a Board of Engineers is not like a complaint you file with the Court. A complaint to the Board is easier to do and anyone can do it. It is free. The Board works for you, not the engineer. The Board's mandate is to serve the public--that's you and I. The Board does not expect you to understand engineering or physics. That's their job. Our complaint is rather unusual because we do understand.

You must direct the complaint against a specific engineer. Do not direct the complaint against a methodology. Do not complain, "You must do something about the yellow durations". The Board does not have authority over methodologies. It only has the authority over the engineer's license. That is as it should be. The Board holds engineers personally responsible for their practice. The Board judges the engineer's competence based on the mathematical and physical sciences. The engineer's methodologies better follow suit.

The Board has the authority to discipline the engineer. Disciplinary actions go on the engineer's permanent record. The Board can fine the engineer thousands of dollars. The Board can charge him with a criminal misdemeanor even for a math mistake. Repeating the math mistake is considered a felony.

Complaints in North Carolina

Engineering Firm Licensure Requirements for Every State

FE Reference Handbook v9.2, Vehicle Change Intervals, p. 164

FE Reference Handbook Solution

This exhibit is not the FE Reference Handbook. This exhibits shows what should appear on page 164 of v9.2 of the FE Reference Handbook.

Glossary of Traffic Engineering Terms

Misapplied Physics in the International Standards Forces Drivers to Run Red Lights

Short Yellows and Turns

Calculate Your Yellow Change Interval--English, Metric

Derivation of the Yellow Change Interval Formula

Retort to "Red Light Cameras Reduce Crashes"

ITE, IIHS, Vanasse, Hangen, Brustlin Response to Ceccarelli's Feb. 2010 Derivation of the Yellow Light Interval Equation

Institute of Transportation Engineers Authority in Question

Dilemma Zone

Approach Speed vs. Speed Limit

Graphs of Cary Camera Data Showing Short Yellows Forcing People to Run Red Lights

MUTCD Rev3, 2022

MUTCD Rev3 Yellow Light Requirements, 2022

MUTCD Rev2, 2012

MUTCD Rev2 Yellow Light Requirements, 2012

MUTCD Rev2--Engineering Requirements Doc

Unsteady Yellow Light Example

MUTCD 4D.26-01 requires the yellow light to be a steady yellow light. In this example red light camera clip, the yellow light is not steady. The light bursts and fades in luminosity. Therefore, this yellow change interval does not comply with the MUTCD. Non-compliance is a crime in all states in the United States.

What is more likely is that the yellow light in reality is steady and what we are seeing is Verra Mobility's doctoring of their video clips. Verra Mobility's video enhancing software alters the video to make the signal lights look brighter than they actually are. What we are seeing is not reality. But Verra Mobility's doctored evidence favors the accused: The yellow light is not in compliance with the MUTCD. So we either see an incompliant yellow light or tainted video evidence. Both are unlawful.

Steven Strength, Louisiana Department of Transportation and Development, P.E., ITE Certified Traffic Engineer

Engineering vs Reality Chart, Steven Strength

Traffic Signal and Red Light Camera Data Required for Analysis

FOIA your city clerk for this information. This is the information you need to analyze a red-light camera program. Be confident that all red-light camera programs are based on engineering malpractice. (You do not need crash data because red-light cameras measure the legal motion of traffic, not crashes. Legal motion of traffic and safety are two different concerns in traffic engineering. One does not imply the other. Though this fact is traffic engineering 101, the public is not aware of it.)

First, FOIA your city clerk for the "red light camera installation plans". The clerk should have these plans available. It usually takes 3 -5 days to get this information. After you receive the installation plans, then you may FOIA the clerk for the rest.

As for the installation plans, be mindful that the longer it takes your city clerk to respond, the greater the odds that the red-light camera firm or city knows it is running an illegal engineering operation. Most of the time (about 80% of the time), the installation plans are not certified by a licensed professional engineer, the camera firm does not have the legal authority to offer engineering services in the State, or the engineer who certified the plans did not have "responsible charge" of the project. All are deliberate crimes.

Second, as for the red-light camera event data, most red-light camera firms no longer disclose event data. The firms do not want outsiders to possess this data. That is because event data damns red-light camera programs. Having the data gives you the power to reveal the nature of red-light running. The nature of the vast majority of red-light running and crashes boils down to systematic engineering failures, not bad driver behavior.

A quick analysis of the data reveals giant disparities in red-light running counts from one intersection to another. Because drivers drive no differently from the east part of town to the west part of town, the only explanation of the disparities is that the engineering or traffic volumes must differ between the intersections. But you will see higher counts at some lower volume intersections.

On closer analysis, the data reveals giant disparities of red-light running counts over periods of time at individual intersections. The differences are caused by traffic engineers, not varying driver behavior. Engineers periodically adjust the signal timing. With the event data, you can literally see the results of their adjustments by noting the increase or decrease in red-light running counts. You will even see that a 0.1 second decrease in the yellow change interval permanently increases red-light running by 50%.

To verify that the change in counts is caused by the engineer, ask the clerk for the "traffic signal plan" or "signal timing chart" for the intersection. These plans and charts must be certified by a professional engineer. Most of the time, they are certified. But there are giant exceptions to this--like in Suffolk County, New York.

Disparities are always explained by engineering changes--for good or bad. Driver behavior is a direct result of engineering, not drivers' ability to drive. When you know the math behind the yellow light, you realize that the disparities, red-light running and crashes are tethered to the traffic engineers' systematic misapplications of physics. You see that red-light running is predictable. You now realize the nature of the red-light camera business. It is a charlatan fraud scheme rooted in misapplications of physics.

Decisions as We Approach an Intersection

Isaac Newton's Principia, Latin (1687)

Isaac Newton's Principia, English Translation (1846)

Newton's Laws Explained by Walter Lewin, MIT (1999)

The Kinematic Equations for Straight Line Motion with Constant Acceleration, 1977

Abstract - Misapplied Physics in the International Standards Forces Drivers to Run Red Lights, 2012

Misapplied Physics in the International Standards Forces Drivers to Run Red Lights, 2013

The Problem of the Amber Signal Light in Traffic Flow, 1959

The Problem of the Amber Signal Light in Traffic Flow--Authors' Biographies

A-Review-Of-The-Yellow-Interval-Dilemma, Liu, Herman, Gazis--1995

Determination of Left Turn Yellow Change and Red Clearance Interval, 2002

Extended Kinematic Equation for Turning Explanation, ITE Journal, March 2020

Extended Kinematic Equation, Mats Jarlstrom, March 2020

Yellow Change and All-Red Clearance Intervals of Physics, Ceccarelli, January 2020

Traffic Signal Change Intervals: Policy, Practices, and Safety, IIHS 1986

Traffic Engineering Handbook, 1965

Transportation and Traffic Engineering Handbook, 1982

Traffic Engineering Handbook, 1999

Traffic Engineering Handbook (Yellow Light Formula), 2010

Traffic Engineering Handbook (Yellow Light Formula), 2016

Traffic Engineering Handbook (Approach Speed), 2010

Speedometer +/- 5 mph, CFR 49 III (2011)

49 CFR III Sec 393.82 allows a speedometer to have an accuracy to +/- 5 mph. If a vehicle is traveling down a road with a posted speed limit of 50 mph but the speedometer reads 55 mph, this opens a 24 foot type I dilemma zone for the driver for straight-through unimpeded movement. The driver can unintentionally run the red light by 0.3 seconds--time enough to trip the red light camera.

Traffic Engineering Handbook (Perception-Reaction Time), 2010

Traffic Engineering Handbook (Dilemma Zone), 2010

Traffic Engineering Handbook (Maximum Dilemma), 2010

Traffic Signal Timing Manual (Yellow Light Formula), 2009

The Dilemma with Dilemma Zones

NCHRP 731 Guidelines for Timing Yellow and All-Red Intervals at Signalized Intersections, 2010

Written by world's premier red light camera proponents (except for Timothy Gates who did not know his name was going on this report), this report is the embodiment of incompetence and corruption. The science does not get any worse.

Within this document one finds 1) misapplication of a physics equation, 2) misapplication of stochastic methods to perception-reaction and vehicle deceleration, omission of the computation of engineering tolerances, the supposition that analytic solutions are physical solutions, and the purposeful intent to make drivers run red lights by assuming drivers are traveling less than the legal speed limit.

For an explanation of how NCHRP 731 is the embodiment of pseudo-science and engineering malpractice, compare with Yellow Change and All-Red Clearance Equations of Physics.

Dilemma Zone Driver Behavior as a Function of Vehicle Type, Time of Day and Platooning, 2010

This study by Timothy Gates is a one-stop shopping resource for perception-reaction times and vehicle decelerations. The conclusions in this paper are consistent with decades of studies. The thing to learn is that perception-reaction time and deceleration are ranges of equally valid values. They cannot be simplified into a one value.

Just as it is improper for a bridge engineer to design a bridge to only support a vehicle of average weight or less, it is improper for a traffic engineer to plug average deceleration and perception-reaction time into the yellow change interval formula. Such practices are called misapplications of stochastic methods.

The picture is a graph of deceleration vs approah speed using Gates' data. (You will find the same graph in Gates' paper.) The picture also presents ITE's deceleration as a blue line. Essentially, ITE screws every driver under the blue line forcing them to run red lights. From Gates' data, you also see that the average deceleration for slower speeds is less than that of average speeds. This deceleration is presented as a red line. Only at 38 mph is the deceleration ITE's value of 10 ft/s/s.

Determining Vehicle Signal Change Intervals, 1994

In the last paragraph on page 5, ITE tells the engineer to set his yellow change intervals so that an acceptable percentage of drivers will run red lights. Local standards define acceptable. To our dismay, traffic engineers actually believe that there such a thing as an acceptable. In previous versions of this paper, 1 to 3% is acceptable. In all versions of this paper, ITE acknowledges that engineers are in control of the percentage of drivers running red lights and so instructs engineers to lengthen the yellow change interval to decrease the percentage. Yet ITE closes its eyes to the legal consequences of the implied reverse: shorting the yellow knowingly producing a high-though-acceptable rate of red light runners.

This version of the paper suggests to the engineer to use law enforcement as a substitute for engineering. This suggestion violates every State law for professional engineers. States mandate professional engineers to safeguard life, health and property, not to knowingly put them at risk.

This version of the paper omits the statement that the ITE yellow change interval may not be appropriate for left turn lanes. The more current the paper, the more inaccurate the statements regarding the meaning of the formula.

Determining Vehicle Signal Change Intervals, 1989

On the top of page 30, ITE tells the engineer to set his yellow change intervals so that an acceptable percentage of drivers will run red lights. In this version of the paper, 1% to 3% defines acceptable as if there is such a thing as acceptable. ITE acknowledges that engineers are in control of the percentage of drivers running red lights and so instructs engineers to decrease the percentage by lengthening the yellow change interval. But ITE closes its eyes to the legal consequences of the implied reverse: shorting the yellow knowingly producing a high percentage of red light runners.

In this version of the paper, ITE does not suggest to use law enforcement. ITE just does not care what happens.

In the middle of page 29, this paper correctly acknowledges that the ITE formula may be inappropriate for protected left turn yellows.

At the end of page 29, this version correctly defines the appropriate yellow change interval as the time it takes the vehicle to traverse the stopping distance required by the reasonable driver.

Determining Vehicle Change Intervals, 1985

This is the original Determining paper. The farther back in time one gets, the more accurate the understand of the ITE yellow change interval formula.

At the top of page 6, this paper correctly acknowledges that the ITE formula may be inappropriate for protected left turn yellows.

In the middle of page 6, this version correctly defines the appropriate yellow change interval as the time it takes the vehicle to traverse the stopping distance required by the reasonable driver.

But in the middle of page 6, ITE also tells the engineer to set his yellow change intervals so that an acceptable percentage of drivers will run red lights. In this version of the paper, 1% to 3% defines acceptable as if there is such a thing as acceptable.ITE acknowledges that engineers are in control of the percentage of drivers running red lights and so instructs engineers to decrease the percentage by lengthening the yellow change interval. But ITE closes its eyes to the legal consequences of the implied reverse: shorting the yellow knowingly producing a high percentage of red light runners.

In this version of the paper, ITE does not suggest to use law enforcement. ITE just does not care what happens.

Yellow Change Interval Origin of Grade, ITE 1982

Perception-Reaction Times, AASHTO 2004

Perception-Reaction Times, AASHTO 2011

Perception-Reaction Times, Oregon State University, 1997

Forensic Aspects of Driver Perception and Response, Olson, 2010

Deceleration Rates, University of Wisconsin, 2007

Commercial Truck Deceleration Rates, Transportation Research Board, 2003

Transit Vehicles Deceleration Rates, USDOT 1977

Truck Air Brake Lag Times, 2009

Guide for Pavement Friction, 2009

Evaluating the Use of Red Light Running Photographic Enforcement, 2004

Retort to "Evaluating the Use of Red Light Running . . ."

IIHS Effect of Red Light Camera Enforcement on Fatal Crashes, 2011

Cameras do not Reduce Crashes - Testimonies from City Officials

Before/After Studies - Deceit and Pseudoscience

Comparing Red Light Running to Crashes

The Scientific Method, Prentice Hall North Carolina 6th Grade Textbook

Ireland Traffic Signs Manual

In 9.2.3, Ireland sets all yellow durations to 3.0 seconds. The error is based on using emergency stopping distances instead of safe and comfortable stopping distances.

ITE International Convention 2015 - Agenda, Florida

Panelists in the Traffic Signals Timing discussion were Richard Retting, Beverly Kuhn and Brian Ceccarelli.

Kuhn spoke about the history of the recommended practice document but did not say anything about signal timings.

Retting pushed his NCHRP 731 report which does everything an engineer should not. NCHRP 731 applies physics equations to traffic movements the equations contradict, misapplies stochastic methods to non-random events (taking averages of p-r time and deceleration), sets stopping distances so that legally-moving traffic does not have the distance to stop, and omits engineering tolerances inherent in the computation of the yellow change interval.

Ceccarelli read a letter by the inventor of ITE's yellow change interval equation, Dr. Alexei Maraudin. Maradudin condemned ITE's misquoting of him in its proposed Traffic Signal Timings Guide and every one of Retting's points in NCHRP 731. Ceccarelli followed up the reading with an explanation of the physics behind the equation, the proper application of stochastic techniques and the concept of engineering tolerances, which traffic engineers did not know applied.

At the convention it appeared that Retting is ITE's choosen traffic signal timing spokesman. Retting's appearance in such a panel is problematic. Retting 1) does not understand basic physics, 2) calls himself an engineer, is not an engineer by license or education, and offers his engineering directly to the public, and 3) is the father of the red light camera industry in America--a lobbyist for Redflex--a conflict of interest.

Physics of the Yellow Change Interval

ITE International Convention, Florida 2015

Autonomous Vehicles Symposium Agenda, 2016

Yellow Change Interval -- Physics in Opposition

Autonomous Vehicles Symposium; Stuttart, Germany 2016

Physics of the Yellow Change Interval

ASCE Luncheon; Raleigh NC 2017

Signalized Intersections Prevent Traveling from Point A to B Legally

Autonomous Vehicles Symposium; Novi, Michigan 2017

Signalized Intersections Prevent Traveling from Point A to B Legally. Acrobat Doc.

Autonomous Vehicles Symposium; Novi, Michigan 2017

Physics of the Yellow Change Interval

Durham Engineers Club; Durham, NC; May 2018

This presentation includes issues legal implications of engineering malpractice.

Engineering Malpractice: Yellow Light Determination, Red Light Camera Systems

St. Benard Conference; St. Benard, Louisiana 2018

Physics of the Yellow Change Interval

North Carolina Society of Engineers, Fall Convention; Blowing Rock, NC 2018

Engineering Core Principles

Majority Leader Report -- The Red Light Running Crisis -- Is it Intentional?, 2001

IIHS - Effect of Turning Off RLCs, 2016