Running a Red-light
is a SNAP!®
Each year hundreds of pedestrians and motorists die as a result of red-light
violations. Many more are injured. According to the National Highway Traffic Safety Administration, which provides
information about traffic and vehicular safety, regulations and standards, research and
development, testing results, injury prevention, and crash information, 39%
of fatal crashes at urban intersections occurred at traffic signals in 1991.
In most jurisdictions a driver commits a violation if he/she crosses the stop
bar (or cross walk) if a traffic signal is red. According to Richard Retting of the
Insurance Institute for Highway Safety: "Deliberate running of red-lights is a common
and serious violation that contributes substantially to [fatal crashes]" (Retting,
The problem is reported nationwide. On Roads
magazine recently published an article on red-light cameras. In that article, the writer
points out that, "Injuries are very likely in accidents involving an ignored
A substantial proportion of motor vehicle crashes in the United States occur at
intersections controlled by traffic signals. This is especially true in urban areas.
According to the National Highway Traffic Safety Administration, 39 percent of fatal
crashes at urban intersections occurred at traffic signals in 1991. (Retting,
Since most cities and counties in the United States use traffic signals in large
numbers, it is generally not practical to provide sworn officers to monitor compliance at
all but a few. Red-light cameras (such as the one manufactured by ATS and shown above can be used to significantly
increase enforcement at a fraction of the cost of using sworn officers.
As one Florida state congressman once said during a legislative discussion on
legalizing photo-enforcement, "Everybody speeds, but running a red-light is against
Red-Light Violators: Who Are They?
An article in U.S. Roads reported on another study by Richard
Retting and Michael A. Green of the Insurance Institute for Highway Safety.
Retting's study found that,
Violators drove older cars than compliers. Thirteen percent of
violator-driven passenger vehicles were manufactured after 1991, while 20 percent of
law-abiding motorists drove vehicles manufactured after 1991. Researchers found passenger
cars, cargo vans, pickups, and utility vehicles equally likely to run the red-light.
However, red-light runners were more likely to drive smaller cars--10 percent of compliers
had cars with a wheelbase of more than 109 inches compared with 6 percent of violators.
Male drivers made up 71 percent of both complying drivers and violating
drivers. Overall, violators were younger, with 26 percent of violators being under 30 and
only 14 percent of compliers under 30. Violators were more likely to be driving without a
shoulder harness--67 percent of red-light runners wore harnesses compared with 71 percent
The study showed that motorists who ran red-lights were often the same
people who had received speeding tickets. The authors stated, Violators were over three
times more likely than compliers to have multiple speeding convictions on their driver
records. Virginia maintains 60-month historical records of driving violations and awards
drivers negative and positive points according to their number of (or lack of)
violations--the higher the point total, the better the driving record. Driving records for
the motorists in this study showed that violators had a lower average point balance than
compliers, and were twice as likely as compliers to have very low point balances. On the
other hand, prior crash figures of Virginia drivers were about the same for the two
groups--13 percent of violators and compliers had a crash on their records.
The Center for Urban Development released this press
release on red light runners in the Fall of 1999.
RED LIGHT RUNNING
IN METROPOLITAN RICHMOND
RICHMOND METRO POLL
Survey Research Laboratory and Center for Urban Development
OVERVIEW OF RED LIGHT RUNNING
Drivers in the Richmond metropolitan area
see red light running as a common problem in the area. When identifying
moving violations they see, Richmond area drivers point out speeding (62%)
and red light running (35%) most frequently. When asked "how often do
you see others run red lights," 27% reported seeing someone run a
light "every day." Another 31% reported seeing someone run a red
light "a few times a week."
Definitions of what constituted
"running a red light" varied. When asked to define running a red
light 67% responded "entering an intersection on red."
Twenty-six percent said that running a red light was "entering an
intersection on yellow but the light turns red while the car is still in
the intersection." Thirty-two percent of respondents said that by
this definition they had run a red light "a few times," while
12% reported having run a light only once. Four percent admitted to having
run red lights "many times."
Reasons for running red lights also varied.
The reasons given by those who had run lights varied from "couldn't
stop in time" (41%) to "in a hurry" (21%). Five percent
claimed to be "Afraid that the car behind them would hit them"
while 4% said that they ran the red light because "no other cars were
Red light running was also related to other
risk behaviors. Drivers who reported that they always wear seat belts were
also more likely to have reported that they never ran red lights (54%).
This compares to those who reported only wearing seat belts most of the
time, less than half the time, or never, only 41% of whom reported never
running a red light.
THE PERCEIVED CONSEQUENCES OF RED LIGHT
One explanation for the prevalence of red
light running is the perceived lack of serious consequences for most
violators. Fifty-nine percent of the licensed drivers thought that l0% or
fewer red light runners would be stopped or ticketed. This perception is
not surprising given the 67% of responding drivers who said that they had
never seen the police ticket anyone for running a red light.
Accidents and injuries were also seen as
unlikely as the result of running red lights. The estimates of how many
crashes would occur as the result of red light running were higher than
those for the likelihood of being stopped or ticketed, but were still
relatively low. Forty-eight percent of the drivers who responded estimated
that 10% or fewer cases of running a red light would result in a crash or
other accident, with 56% of those who predicted accidents estimating a 10%
or less chance of injury in such an accident.
METHODOLOGY OF THE SURVEY
The data for this study were collected
through telephone interviews with adult informants in a randomly-selected
sample of 810 households in the Richmond Metropolitan area (Richmond City,
Chesterfield, Hanover, and Henrico Counties) between February 28 and March
10, 1996. Interviewing was done at the facilities of the Survey Research
Laboratory at Virginia Commonwealth University in Richmond. The random
digit dialing sample of telephone numbers was prepared by GENESYS Sampling
Systems of Fort Washington, PA.
Data collection utilized a
computer-assisted telephone interviewing system (CATI) to administer the
questionnaire to respondents. In this system, questions for the survey are
displayed on a computer screen from which the interviewers read the items.
Responses are keyed directly into the computer. In addition to the
substantive modules of questions, interviewers also ask a series of
demographic questions. Responses were weighted by race and education to
better reflect the actual metropolitan Richmond population. Percentages in
the tables are weighted, while the number of cases listed for subgroups
represents the actual number of individuals interviewed.
Users of the data should be aware of the
limitations of the survey method. When respondents are asked to respond to
questions concerning illegal behaviors, some responses can be expected to
be unreliable. However, this problem of self-identification can be
expected to be less severe in the case of behaviors, such as those
discussed here that are not considered highly stigmatizing.
Questions answered by the entire sample of
810 respondents are subject to a sampling error of plus or minus
approximately 4 percentage points at the 95 percent level of confidence.
This means that in 95 out of 100 samples like the one used here, the
results obtained would be no more than 4 percentage points above or below
the figure that would be obtained if all of the adults with telephones in
the Richmond metropolitan area had been surveyed. Where answers involve
subgroups of the overall sample, sampling error can be expected to be
higher. It must also be understood that surveys are also subject to error
from causes other than sampling. Every effort has been made to identify
and correct for such causes. However, in most cases they are impossible to
accurately measure. Therefore, readers making use of the results are urged
to keep these limitations in mind.
WORDING OF SELECTED QUESTIONS
Now, on a different subject... Are you a
licensed driver? When you are driving, what traffic violations do you see
other drivers committing? Mention as many as you recall. I'd like to take
a minute to discuss red light running. How do YOU define running a red
light READ RESPONSES <1> Entering an intersection on yellow but the
light turns red while the car is still in the intersection or <2>
Entering an intersection on red. How often do you see others run red
lights? READ RESPONSES <1> Everyday <2> A few times a week
<3> A few times a month or <4> Less than once a month. Have
you ever seen the police ticket someone who has run a red light? Have you
ever run a red light as you described it? IF YES: Was that one time, a few
times, or many times? Out of 100 drivers who run a red light in [fill],
how many do you think will actually be stopped and ticketed by the police?
Out of 100 instances where someone runs a red light in [fill], how many do
you think will result in a car crash, hitting a pedestrian or a cyclist?
In how many of these cases do you think someone will be hurt? How often do
you wear a seat belt when you drive? READ RESPONSES <1> Always
<2> Most of the time <3> Less than half the time <4>
Never. About how many miles per year do you drive? Have you ever gotten a
ticket for a moving violation? IF YES: Was that one time, a few times, or
many times? Have you ever taken a driver education course?
DEPARTMENT OF MOTOR VEHICLES MODULE
|When driving what
moving violations do you see?
|Drunk or drugged driving
|No full stop at sign
|Failure to signal turn
|Running red light
All percentages are weighed
Sampling error for questions answered by ALL respondents is approximately
Sampling error for subpopulations will vary and are higher than that for
the full sample.
DEPARTMENT OF MOTOR VEHICLES MODULE
|RED LIGHT RUNNING
|Enter intersection on yellow/turns
|Enter intersection on red
|How often do you see
others run red lights?
|A few times a week
|A few times a month
|Less than once a month
|Have you ever run a
red light as you described it?
|Yes, a few times
|Yes, many times
All percentages are weighed
Sampling error for questions answered by ALL respondents is approximately
Sampling error for subpopulations will vary and are higher than that for
the full sample.
DEPARTMENT OF MOTOR VEHICLES MODULE
|RED LIGHT RUNNING:
|Have you ever seen
ticketed for running a red light?
|Seen someone ticketed near
light/Don't know why
|How many out of 100 do
you think will be ticketed?
|51 or More
|How many out of 100 do
you think will lead to crashes?
|51 or More
All percentages are weighed
Sampling error for questions answered by ALL respondents is approximately
Sampling error for subpopulations will vary and are higher than that for
the full sample.
What is the "Red Light Running" Campaign?
The "Red Light Running" campaign is a
comprehensive safety outreach program developed by the Federal Highway
Administration (FHWA) which incorporates public information and education
with aggressive law enforcement. Communities joining this campaign will
receive public service announcements (PSAs) for
television, radio and print, as well as technical assistance from FHWA
and their contractor, a social marketing firm. Armed with these tools and
start-up funding, selected communities can customize the campaign to meet
their local needs.
Is running red lights a serious problem?
According to the Insurance
Institute for Highway Safety, disregarding traffic controls is a
leading cause of urban crashes in the United States today, representing 22
percent of the total number of crashes. The economic impact of these
crashes is estimated at $7 billion each year in medical costs, time off
work, insurance hikes, and property damage.
Why is the Federal Highway Administration involved in
Coupled with FHWA's mission to provide the nation
with safe and efficient transportation, is the agency's commitment to
expand public outreach efforts. Increasing awareness of road way-related
issues can only serve to enhance safety for the traveling public. This
translates into a health and economic benefit for the entire country.
How was Red Light Running selected as a public outreach
Nearly four years ago, representatives from FHWA
field offices and headquarters met to discuss ways to enhance the public's
understanding of the agency and its purpose, specifically as it relates to
roadway safety. Among the topics generated by participants, was the
public's disregard for traffic signals and signs.
The FHWA is responsible for establishing
standards for all traffic control signals and signs used on public roads.
Participants felt that the public's compliance with signals is
deteriorating and more importantly, that the public's perception of the
dangers of running a red light is also diminishing. Subsequent focus group
research found that the public is losing sight of the purpose of the
signal and many felt that signals and their timing cycles were arbitrary.
Was Red Light Running pilot tested prior to this
Campaign materials were pilot tested last summer
in a three county area surrounding Charleston, South Carolina. The
Trident/ Charleston area was selected because it had a documented crash
problem at intersections with signals; the traffic signal system was not
the cause of this problem; the business community was a strong supporter
of various traffic safety initiatives; and the local enforcement agencies
demonstrated a willingness to enforce RLR violations. The RLR pilot
campaign was extremely successful, with a 48 percent viewer recognition
rate of PSAs and a reduction of traffic crashes at intersections with
signals. These results, coupled with post-campaign focus group research,
were instrumental in the decision to implement the RLR campaign
How was the RLR campaign introduced to communities
across the country?
The results of the RLR pilot test were showcased
in a technical panel at the annual meeting of the National Association of
Governors' Highway Safety Representatives (NAGHSR) which was held in
Sacramento, California last September. NAGHSR members enthusiastically
embraced this new safety outreach initiative and endorsed its national
implementation. Following campaign overview sessions in each of FHWA's
nine regions, FHWA field staff marketed the RLR campaign to communities
across the country and invited them to apply for implementation grants. In
addition, FHWA sponsored an RLR workshop at Lifesavers 13 last April in
Indianapolis, Indiana. Lifesavers is the nation's largest traffic safety
conference and draws representatives from a variety of disciplines
concerned with traffic safety issues.
What was the grant selection process?
Community organizations around the country,
including police agencies, county governments and community coalitions,
applied for "Red Light Running" grants through a detailed
application process. Selection criteria mirrored those established for the
pilot site: namely, the documentation of a red light running problem; an
assurance that communities' signal systems meet federal standards and are
operational; a community structure equipped to implement this type of
outreach campaign; and the support of law enforcement agencies. An FHWA
selection committee rated all applications against these criteria. The
response was overwhelming and each applicant will receive a complete set
of RLR campaign materials and technical assistance from FHWA headquarters.
In addition, RLR grants will be awarded to the top 32 community
How much grant money will be awarded in total?
Over $600,000 will be disbursed among the
selected communities. In addition, PSAs will be individually tagged for
each community and technical support and marketing assistance from the
contractor will be available throughout the length of individual community
Why is this campaign being implemented on a local
versus national level?
Local organizations, safety coalitions, and law
enforcement agencies are uniquely qualified to implement community
What is the primary objective of the campaign?
The basic objectives of the RLR campaign are to
reduce traffic crashes and serious injuries, as well as the economic costs
these crashes impose on communities. The RLR campaign materials underscore
the hazards associated with red light running and are intended to raise
awareness of this traffic safety issue among the motoring public.
How will you judge the success of the campaigns?
Communities will conduct surveys to gauge
community awareness of and attitudes towards signal compliance, gathering
and analyzing RLR citation statistics and crash history, and conducting
observational studies of cars running red lights at selected
intersections. Once the national RLR campaign is completed, FHWA will
produce a final report summarizing the findings.
How does the Federal Highway Administration's Red Light
Running campaign tie in with using cameras for enforcement?
The FHWA Red Light Running program is a public
information and education campaign that is to be implemented with
aggressive law enforcementwhether it involves assigning offic ers to
patrol high hazard locations or installing automated equipment at key
intersections. In fact, one of our television public service announcements
revolves around a law enforcement theme with a powerful message: law
enforcement intends to stop red light runners for their own good.
Red Light Running PSA
The following story board was adapted from a public
service announcement developed by the Federal Highway Administration.
For More Information
For more information about the Red Light Running
Campaign, contact Mila Plosky at:
FAX: (202) 366-2249
Red-light cameras are fully automated systems designed to photograph, under any
weather or light condition, vehicles in violation of a red traffic signal. The initial
purpose of the red-light camera is to provide, through sequential photographs,
indisputable evidence of red-light offenses. Similar cameras, used in over 40 countries
worldwide, are designed to supplement the police force and provide:
- Law Enforcement
The use of red-light cameras benefits the public as well as municipalities.
red-light cameras usually can be used only if appropriate legislation is enacted. Such
legislation often results in quite different methods of enforcement. In New York, for
example, the registered owner (owner onus) is held responsible for a violation committed
with his vehicle. In many respects the ticket generated is similar to a parking ticket.
For this enforcement only rear photography is needed. In California, however, the driver
is cited with a moving violation. Thus a photograph must clearly show the driver of the
The red-light programs are effective. In New York City, of all the red-light
tickets issued in December, 1993, 67% were issued by police officers and 33% were issued
by the Citys fifteen red-light cameras. (A total of 295,414 red-light tickets were
issued by the entire NYPD in 1993.)
Warrants are justifications for installing traffic control devices such as
signals, stop signs, etc. They are often well defined for such control devices. The
following warrants for photo-enforcement of traffic signals are intended as a guide to
determining whether an intersection is appropriate for the installation of a red-light
- Accident History
- Is there a history of traffic accidents at the intersection in question?
- The greater the number, the more there is evidence of a problem.
- Traffic Citation History
- Is there a history of traffic citations having been issued at the
intersection in question?
- Often more an indicator of available police resources and the relative safety of
enforcing the law, however, this is still an indicator of a problem.
- Neighborhood Complaints
- Is there a history of complaints regarding the danger of the intersection?
- While not always an indicator actual accidents, this is a strong indication of
- Traffic Volumes
- What volume of vehicles traverse the intersection from each direction?
- The greater the volume, the greater the likelihood of violations.
- What are the speeds of vehicles approaching the intersection?
- The greater the speed, the more likely a red-light violation, and the more
dangerous any resulting accidents.
- Cost to Install the RLC
- Are there are special circumstances which increase or decrease the cost of
installing the RLC system?
- Examples include how much conduit has to be jacked under the street, the
availability of power, etc.
- Planned Near-Term Road Improvements
- Is there any construction work on the intersection which may damage the RLC
system, particularly the roadway loops?
- This would suggest delaying the work, so as to avoid the cost of re-installing
any components which may be damaged during such work.
- Other Solutions
- Are there other solutions (engineering, education) which are practical and
- If so, these may be more appropriate. Examples may include re-timing the traffic
light sequence, or that of preceding intersections, re-positioning of traffic lights, etc.
Designing, developing, and implementing a red-light system involves assembling a
diverse collection of resources: capital, hardware, software, people, time, and training.
Putting these resources together in a meaningful way, finding and training appropriate
staff, and managing the entire process is usually referred to as 'systems integration.' It
is analogous to building a house by purchasing hammers, nails, wood, windows, doors, etc.
from hardware store, hiring carpenters, electricians, and plumbers, and supervising the
entire process with or without a blueprint.
The task of implementing a red-light camera monitoring system can be
accomplished in several ways, from developing and operating the entire system in-house to
complete outsourcing. That is, just as in building a house, one can choose to buy the
materials and build the house (assuming one has the time, skills, and a blueprint), hire
sub-contractors to do most of the actual work, or simply hire a home builder to manage the
entire project. So it is in implementing red-light camera systems. A jurisdiction may
choose to serve as a general contractor or hire one as a systems integrator, or outsource
the entire process.
Jurisdictional resources include time, capital, personnel, and facilities. The
impact of these resources should be kept in mind as each of these options is reviewed:
- Build in-house
- Use systems integrator
- Use systems manager
- Use outsource or process management company
The decision to "build or buy" should be made carefully.
Red-light camera monitoring systems are automated computer-camera systems
designed to photograph, under any weather or light condition, vehicles in violation of a
red traffic signal. Through sequential photographs, the red-light camera provides
indisputable evidence of red-light violations.
Choosing to capture frontal, rear, or both images is usually mandated by state
law. Rear photographs are frequently made in states (e.g., New York and Virginia)
where owner onus is the law, that is, the owner of the vehicle is responsible
regardless of who the driver is. This is usually the case in parking citations. In states
where driver identification is required (e.g., California), frontal photography is
required. In states requiring positive driver identification but not requiring front
license plates (e.g. Arizona), both front and rear photographs are required.
cameras capture red-light violators on 35mm photographic film. The cameras are
computerized and usually record date, time, and location on each frame in a data bar or
block. The cameras are usually tied directly to the traffic signal system and are active
only during the red phase of the traffic signal cycle. The photo at left is typical. It is
part of a pair of photographs from New South Wales.
Notice that the traffic signal is clearly red in both photographs as the white car passes
through the intersection.
A pair of
Electromagnetic induction loops are embedded in the crosswalk area
of each lane to be monitored. These serve as the triggering mechanism for the red-light
camera. The red-light camera is connected to the loops and to the red phase in the traffic
signal pole. During the green phase of the traffic signal cycle, the unit is deactivated
and photographs can not be taken. During the amber phase the unit is automatically
switched to stand-by, and with the start of the red phase the camera is activated after an
initial delay specified by a jurisdiction. often .3 seconds.
When a vehicle passes over the loops during the red phase, the first photograph
is taken documenting on the film the red phase, the vehicles prior point relative to
the intersection and a number of supportive data in a data field of the picture and
optionally on a memory card in the unit. A second photograph is taken within a
predetermined time frame based on the speed of the vehicle (usually .5 - 1.1 seconds)
documenting the vehicles position in the intersection.
As mentioned above, a data bar or block is usually placed on the negative at the
same time it is exposed. The data block used on the Gatso camera is described by the Oxnard, CA Police Department,
"On every photo is a "Camera Data Block." This block (enlarged from the above photo) can tell us
many things about the violation. This picture was taken on July 7, 1997 at 5:50 p.m. and
was the eighth photo citation of the day at this intersection. This is the second of two
photos taken of this car. The first photo was exposed 0.5 seconds prior to this shot. At
the time of this photo, the light had been red for 0.9 seconds and the speed of the car is
58 miles per hour.
The film is collected and processed on a regular basis, often daily. Any change
to the system or the cameras including vandalism -- noted during film retrieval
should be documented and presented to the jurisdiction
Not all photographs can be used to issue citations The number of photographs
that result in citations occurring during any one calendar month could be affected by:
- Weather (Snow, Ice)
- Number of days in the month
- Seasonal variations in traffic patterns
- Technical problems (Camera malfunction, loop damage)
- Exempted Vehicles (Police, Fire, Diplomat, etc.)
Red-light camera systems are usually composed of three main subsystems:
- Control mechanism
- Violation Detection
Automated red-light cameras usually capture images of red-light violations on
35mm photographic film in B&W or color. Similar to standard 35mm cameras but
manufactured to more rigorous standards, red-light cameras are able to withstand years of
continuous operation in a variety of conditions. While most systems in place today use what
is called the "wet film" technology available since before the turn of the 20th
century, some companies are distributing Digital systems.
Some of the digital systems use digital or Video Cameras to record the violation. Some systems provide an
optional real-time video system to monitor traffic and record collisions on video tape. A
video system may be connected to a central dispatch facility in order to provide immediate
information and expedite appropriate response and notify law enforcement personnel.
Several companies such as SD Scicon, Econolite, and Peek Traffic Systems offer video
systems that can be used to monitor intersections. While a violation may be detected with
video cameras, sophisticated computers and software using a trigger known as a "photo
loop", a still camera is usually required to capture the violation because of the
placement of the video camera (high above the intersection) and a desire to use film -
instead of videotape - as the evidentiary media.
Standard red-light cameras include computers which record the date, time,
seconds into red, location code, superimposed onto each photograph. Lane number, vehicle
speed, and seconds of amber may also be recorded. The red-light camera computer also
handles the triggering function.
Red-light cameras are activated when a vehicle crosses a trigger during the red
phase of a signal. The trigger is usually specially designed loops but may include Piezo
strips or even radar beams. The trigger activates a camera placed behind the vehicle, in
front of the vehicle, or sometimes both.
Red-light cameras are placed and controlled at the discretion of a jurisdiction.
Since they are connected to the red phase of the traffic signal (preferably through
opto-isolation circuitry) and only active during the red phase, the probability of false
triggering is remote. Additionally, a jurisdiction may choose to add a speed threshold and
activation delay. A speed threshold is used to prevent the false triggering of vehicles
which sometime creep over the loops. This is usually 5-15 mph. An activation delay may be
used by a jurisdiction if it wishes to give the motorist a grace period after the signal
turns to red. When used, this delay is usually not more than 3/10ths of a second.
In order to be able to photograph a traffic violation, some mechanism must be in
place to accurately determine when and if a violation has occurred. Traditional
enforcement has often relied on the eyes and judgment of a uniformed police officer. The
use of automated detection equipment, however, is much more accurate and cost effective.
Detection equipment ranges from the simple air tube to complex Radar or laser.
The enforcement application, of course, determines the detection method used.
Speed violations are usually detected with radar. Many red-light cameras are capable of
measuring speed as well and can be combined with red-light monitoring to provide more
intersection monitoring and enforcement. The technique is used successfully in Great
Triggers are mechanisms that activate the recording equipment when a violation
occurs. Many devices can be used. Some common ones include air tubes, loops, Piezo strips,
RADAR, and Laser.
One of the simplest trigger is the air
tube. These are rubber tubes (much like a garden hose) that are placed across a roadway.
When a vehicle crosses over the tube, air is compressed inside the tube and a pressure
sensitive switch at one end is triggered. While simple, air tubes are almost never used
for monitoring intersections for more than a brief period due to the limited life of an
air tube. However, they are very effective when coupled with a traffic counter such as the
Mitron 3000 (shown at left) to determine
the need for a red-light or rail crossing camera.
A vehicle detection system is frequently composed of a digital loop detector and
inductive loop wires embedded under the road surface. This combination provides a highly
sensitive detection field for sensing offending vehicles within the detection zones. A
rectangular loop detector zone is used to ensure that all vehicles entered the zone along
the same axis, and that the intensity of the magnetic field was equal throughout the zone.
This configuration has proven to be very successful in detecting and photographing
vehicles that are running a red-light or going under or around a rail crossing arm during
the red signal sequence.
The digital detection system usually allows the system to accurately monitor
both the direction and speed of vehicles traversing the detector loops. The direction
sensitivity allows the unit to require that a given loop be tripped before another in
order for a violation to be recorded.
Loop detectors used in photo-enforcement are usually of the scanning type. That
is, they are switched on and off in series very quickly. This reduces the amount of
interference from adjacent loops since no two loops are actually active at any one time. A
fast scan ensures that they always appear on. Many are able to accurately measure speed as
well. This technique is used to allow the unit to monitor traffic from various directions.
For example, direction sensitivity is achieved when the central processing unit (CPU)
receives a message from the loop detector that a vehicle was sensed encroaching on loop 1
or loop 2 followed by loop 3 or loop 4 respectively. Vehicles traveling in the other
direction should not activate the unit.
Speed sensitivity allows the service personnel to set the system to only
photograph violators exceeding a minimum speed threshold. This sensitivity is especially
useful in determining the speed of a vehicle as it is illegally crossing the grade or
intersection, or simply to help preserve film by not photographing vehicles that just
happen to rest on the detection loops during the red phase. Thus, if the service personnel
set the minimum speed to 5 mph, the unit will only photograph violators passing over the
loops at a speed of 5 mph or above. However, scanning detectors are not often used when
accurate speed measurement is required because the scan rate may affect the time increment
measured from loop to loop.
Speed sensitivity is of great importance since each violation has recorded in
the data box or bar the speed at which the vehicle passed through the highway-railroad
intersection. In most cases, this information serves as additional evidence that the
offending driver had sufficient time to stop the vehicle before entering the crossing, or
that the driver simply was proceeding through the highway-railroad intersection at a high
rate of speed with no intention to stop. An additional benefit of setting a minimum speed,
is that vehicles that come to rest on the detection zone during the red phase will not
cause the unit to be triggered since their speed is 0 mph.
Correct installation of loops is critical. Placement, choice of materials and
thorough testing are very important.
Inductive loops are usually composed of three - five turns of #14
XHHW - XLP (or other) Loop wire buried in a 1/4 to 3/8 inch saw cut 2.5 - 5 inches deep.
The inductance of each loop should be between 100-350 microH, with no more than 15%
variation between loops at any one site. Lead-in cable normally has an inductance of
approximately .22 microhenries (uh) per foot as shown in the first equation below. The
second equation below can be used for approximating the inductance of a single square or
rectangle loop. (Detector
Systems, 1). Loops should be sealed with a 3M Elastomeric sealant or equivalent.
- Lc=Inductance of lead-in Cable (uh)
- lc=Length of lead in Cable
- Lu=Unit inductance (uh/ft)
- L=Inductance (uh)
- P=Perimeter (ft.)
- N=Number of turns in loop
Loops are usually placed .5 m to 5 m apart front to back on center depending on
the anticipated speed of traffic. Loops should be placed no closer that 1 m side to side.
Loops for use with higher speed traffic area usually placed farther apart. Standard 6' x
6' diamond or round loops are not suitable for red-light camera triggering. While these
are a standard shape for traffic monitoring needing only simply presence detection,
smaller loops are more effective for passage detection required for red-light camera
triggering (Farradyne, 2).
Loop wire is connected to loop detectors. They are used to detect changes in
inductance in the loop wires caused by the presence of high mass objects such as cars.
These are usually standard NEMA, four channel scanning detectors with autotuning, variable
sensitivity, fault detection, and presence and pulse modes. They are usually included with
the red-light camera system.
Marshal Brain's outstanding web site, How
Stuff Works recently answered a question about how loops work.
of the Day
Each weekday Marshall
Brain answers questions submitted by the readers of How
Stuff Works in the Question
of the Day section of HSW. You can also view previously
answered questions in the HSW
Question Archive. Here is today's question!
How does a traffic light detect that a car has pulled up and is
waiting for the light to change?
There is something exotic about the traffic lights that
"know" you are there - the instant you pull up they
change! How do they detect your presence???
Some lights don't have any sort of detectors. For example, in a
large city the traffic lights may simply operate on timers. No
matter what time of day it is there is going to be a lot of
traffic. In the suburbs and on country roads, however, detectors
are common. They may detect when a car arrives at an intersection,
when too many cars are stacked up at an intersection (to control
the length of the light), or when cars have entered a turn lane
(in order to activate the arrow light).
There are all sorts of technologies for detecting cars -
everything from lasers to rubber hoses filled with air! This
page has a nice catalog of technologies. By far the most
common technique is the inductive loop. An inductive loop
is simply a coil of wire embedded in the road's surface. To
install the loop they lay the asphalt and then come back and cut a
groove in the asphalt with a saw. The wire is laid in the groove
and sealed with a rubbery compound. You can often see these big
rectangular loops cut in the pavement because the compound is
Inductive loops work by detecting a change of inductance. To
understand the process, let's first look at what inductance is.
This figure is helpful:
What you see here is a battery, a light bulb, a coil of wire
around a piece of iron (yellow) and a switch. The coil of wire is
an inductor. If you have read the HSW article entitled How
Electromagnets Work, you will also recognize that the inductor
is an electromagnet.
If you were to take the inductor out of this circuit, then what
you have is a normal flashlight. You close the switch and the bulb
lights up. With the inductor in the circuit as shown, the behavior
is completely different. The light bulb is a resistor (the
resistance creates heat to make the filament in the bulb glow).
The wire in the coil has much lower resistance (it's just wire),
so what you would expect when you turn on the switch is for the
bulb to glow very dimly. Most of the current should follow the
low-resistance path through the loop. What happens instead is that
when you close the switch, the bulb burns brightly and then gets
dimmer. When you open the switch the bulb burns very brightly and
then quickly goes out.
The reason for this strange behavior is the inductor. When
current first starts flowing in the coil, the coil wants to build
up a magnetic field. While the field is building, the coil
inhibits the flow of current. Once the field is built then current
can flow normally through the wire. When the switch gets opened,
the magnetic field around the coil keeps current flowing in the
coil until the field collapses. This current keeps the bulb lit
for a period of time even though the switch is open.
The capacity of an inductor is controlled by two factors: 1)
the number of coils, and 2) the material that the coils are
wrapped around (the core). Putting iron in the core of an inductor
gives it much more inductance that air or any other non-magnetic
core would. There are devices that can measure the inductance of a
coil, and the standard unit of measure is the henry.
So... Let's say you take a coil of wire perhaps 5 feet in
diameter, containing 5 or 6 loops of wire. You cut some grooves in
a road and place the coil in the grooves. You attach an inductance
meter to the coil and see what the inductance of the coil is. Now
you park a car over the coil and check the inductance again. The
inductance will be much larger because of the large steel object
positioned in the loop's magnetic field. The car parked over the
coil is acting like the core of the inductor and its presence
changes the inductance of the coil.
A traffic light sensor uses the loop in that same way. It
constantly tests the inductance of the loop in the road and, when
the inductance rises, it knows there is a car waiting!
Here are several interesting links:
After loops are installed, it is important that they be thoroughly tested. A
loop testing device can be used to test both continuity and loop insulation resistance.
One such device is the Model ILA-550 Inductive Loop Analyzer from Detector Systems which
can measure leakage resistance, frequency, and relative signal strength, loop inductance,
resistance, and change in inductance.
Another type of loop being manufactured today is the earth
magnetic loop (EML) made by 3M. Unlike surface mounted loops, EML are installed in a small
hole drilled into the pavement. Since they are responsive to changes in the earth's
magnetic field, they are installed cable side up north of the equator and cable side down
south of the equator.
These may be useful in situations where other loops already exist. 3M markets
the product under the name Microloop Probe 701. According to 3M:
The Microloop Probe is a small cylindrical passive transducer of earth's
vertical magnetic field into inductance. It transforms changes in magnetic field intensity
into inductance changes which can be sensed by loop detector units. Intended for point
detection (passage) application, 1, 2, or 3 microloops installed across a lane will
replace a typical 3 turn 6' x 6' wire loop for those applications (3M, 1995).
Microloops will usually not work in the vicinity of rails other large metal
objects and are thus not suitable for rail crossing enforcement.
Piezo strips work on the principle of physics know as the piezoelectric effect.
Simply stated, the Piezo effect is the generation of an electrostatic voltage as a result
of compressing a quartz crystal. The strips are usually set in the roadway and protrude
above it only slightly. This may create a problem however if the jurisdiction or other
agencies require buried sensors.
When a vehicle crosses the strip the weight of the vehicle compresses it and
generates a voltage that then is used to trigger a timer. A pair of Piezo strips can be
used to measure speed, but are used almost exclusively at intersections and not highways.
Piezo strips provide the most accurate detection and
triggering especially when combined with loops.
development in triggering makes use of a PC to create virtual loops using software, signal
processors, and a video camera. As the image of an intersection is received, changes in
the frame are compared to predefined screen areas and used to trigger counters and
According to Michalopoulos, the creator of the AUTOSCOPE concept.
...the system can detect traffic in multiple locations within the
camera's field-of-view. These locations are specified by the user in a matter of minutes
using interactive graphics and can be changed as often as desired. This flexible detection
placement is achieved by placing detection lines, using a mouse, along or across the
roadway lanes on a video monitor displaying the traffic scene. Since these detection lines
exist only on the monitor and not in the pavement, they can easily be removed or adjusted
following initial placement (Michalopoulos
Loops drawn with a mouse can be logically combined with each other using Boolean
logic to create sophisticated patterns. These systems are marketed for use in accident
detection, intersection and highway management, freeway ramp control, vehicle counting,
turn and traffic direction monitoring as well as enforcement. Recognized benefits include:
- Non-destructive to road structures
- Real-time monitoring
- Complete intersection/roadway control
- Easily reconfigured
Initially products of this type suffered problems caused by vibration and sharp
edged shadows, but these seem to have been resolved. The cost of installing them is
generally equivalent to other monitoring types when eight or more lanes of traffic are to
be monitored at any one location. Several companies manufacture systems based on this
technique including Odetics, Peek Traffic, and Autoscope.
Using LASER beams reflected from the roadway DSS' RED EYE 77 Digital red-light
camera System is an increasingly popular alternative to loops. According to
The RED EYE 77 is an automated fully digital red-light camera system,
capable of monitoring up to four lanes of traffic. Using state-of-the-art electronic still
photography, the system generates high resolution digital photographs of all violators
traveling through red-lights.
High resolution traffic cameras provide wide angle intersection photographs and
zoomed-in views of the front or rear license plate of the offending vehicle plate (the
system can be customized to show the drivers face). Two digitized photographs of each
violator are produced. The photos, along with all technical violation data, are saved on
convenient Digital Audio Tapes or WORM-CD. Optional encryption technologies can be used to
preserve the integrity of the data generated. A data communications system instantaneously
relays all data, via telephone or wireless systems, to a central Data Processing Unit
where citations are automatically printed.
An undetectable, infra-red flash option is also available.
As discussed above there are many factors to be considered in installing a
red-light camera system. To summarize the steps:
- Review the laws regulating photo-enforcement
- Determine the need using the warrants listed above.
- Solicit community support for photo-enforcement
- Select a camera vendor and/or systems integration company
- Select probable locations
- Evaluate these location using a device such as the Mitron® Traffic Counter
- Engineer the locations:
- Select number of lanes to be covered. Generally three lanes going in the same
direction is the maximum for film based system and one to two lanes for
- Select the number of cameras.
- Select placement of each camera.
- Select film type and speed
- Select lens
- Select appropriate filters
- Determine number and location of flash units
- Determine location of loops
- Obtain engineering drawing of proposed installation
- Construct site
- Test system
- . Have as built drawings completed.
While installing red-light cameras is similar to installing a traffic signal, it
does involve technologies not usually used in most jurisdictions traffic departments.
Since the public often becomes very interested in a project of this type a jurisdiction
should insure that the necessary skills are available in-house or from a vendor whose
primary business is photo-enforcement.
For any public safety program to succeed it must have the approval and support
of the citizenry. In this section we briefly review some aspects of citizen services
which may impact the effectiveness of an automated enforcement system.
Besides seeing the cameras on the street, citizens will be involved in a
red-light camera program through the following jurisdictional activities:
- Warning Signs
- Public Awareness Campaign
- Press Conference and Equipment Demonstration
- Police Department and State Personnel Familiarization Training
- Help Desk
- Hearing Scheduling
- Information Access
Photo Enforcement Warning Signs
Signage informing citizens about the use of photo-enforcement may be placed at
the jurisdictions discretion or may be mandated by law. Signs may be placed at every
location or at major entrances to a jurisdiction. Some jurisdictions e.g. New York
City have chosen to maintain a stealth program where no signage is used.
Public Awareness Campaign
The objective of a public awareness campaign is to ensure that no one receives a
notice without being forewarned. This strategy can outline the community education program
designed as an on-going dialogue with community organizations, neighborhood associations,
and schools. This strategy might also include a detailed plan consisting of a timeline,
schedule of events and appearances, list of organizations and groups, and proposed
community education strategy.
Press Conference and Equipment Demonstration
If desired, a major kick-off event designed to educate the community about the
objective of the program as a means to improve traffic safety can be scheduled. The press
conference could feature local and state officials, supportive residents and community
leaders as proponents of the program.
Police Department and State Personnel Familiarization Training
Just as it is critical for the public to be informed about the implementation of
a new photo-enforcement program in their community, local law enforcement and jurisdiction
personnel must be provided with the information necessary for adequate support and
administration of the program. Training sessions should be scheduled for all key personnel
within the jurisdictions operational structure.
Notices of Violation will result in citizen inquires. Staff must be provided to
answer questions from both phone calls and walk-ins. The functions are usually
incorporated into a centralized help desk.
A scheduling component provides the capability to schedule hearings for
defendants. the system should allow for multiple courtrooms at multiple locations. In
addition to scheduling, a scheduling system should allow rescheduling, canceling, and
drop-in scheduling as well. Scheduling could be performed by Help Desk employees or as a
dedicated position, depending on volume.
Correspondence may come directly to the jurisdiction or may come through the
lockbox process. In either case, correspondence is usually composed of complaints or
denials of guilt or liability. If a reply is appropriate, it is necessary to link the
writer to a particular alleged violation. Correspondence must be stored for future
reference. this can be done manually or the correspondence can be captured electronically
and stored with data and photos.
Depending on the volume of inquires, it may be appropriate to install automated
voice response units to handle inquires, and hearing scheduling, or to allow payments by
credit or debit card.
|Location of employees
|Reprint Citations on demand
||Yes, No, Credit card
|Automated voice response
Considering the assumptions given above, five to six employees are required to
perform functions in conjunction with other help desk duties.
Public relations, PC keyboarding, and MS windows or other GUI training is
required. Two to four days of training should be sufficient.
Equipment used to actually capture an image of a violation is basically
the same regardless of manufacturer. A camera is attached to a computer controller and
together they are housed in a metal box mounted on a pole.
The camera must be a high precision scientific-industrial 35mm wet film or
digital device designed exclusively for traffic photography. It must have been designed to
capture high quality images with superior resolution, in varying environmental and
lighting conditions. A high speed shutter capable of 1/1000 of a second exposures combined
with a synchronized flash are necessary. Image capture (photographs) must occur at a rate
of two frames per second or better. Cameras may by used to capture both front and rear
license plates, as required.
Most reliable cameras are specifically designed for operation in an unattended
environment and incorporate a user-friendly configuration to allow service personnel to
set all functions for on-site automatic deployment. Most operation of the camera do not
require any adjustments for external lighting or focusing, as this should all be done
automatically by a built-in automatic aperture control system, which should continuously
adjusts the lens aperture for varying lighting conditions during the day. Thus, each image
is exposed at the proper setting automatically both day and night. The camera should be
able to be used with 35mm film, including color, black & white, and infra-red,
at ASA 25 to 1600 and film lengths of 12 exposures to 800 exposures. Film should be able
to be easily loaded and unloaded without any special equipment. Both standard and bulk
film must be secured onto the camera by a single lever mechanism to ensure proper
alignment of the film.
The camera should employ advanced optics technology such as the Schneider
Tele-Xenar lens which is manufactured to deliver an image of sharp quality and high
resolution. Schneider is recognized as one of the world's premier lens manufacturers.
These lenses were designed specifically for high-speed traffic photography in conjunction
with the traffic camera.
The Camera must be capable of night time operation, allowing the operator the
flexibility of using a variety of film types for all lighting conditions. An automatic
diaphragm control is necessary to allow the camera to instantly adjust the lens opening
for operation at low levels of ambient light, and at all available film speeds.
The Control System
All functions associated with the operation of the system are usually programmed
on-site through a user friendly, menu driven input system. The service personnel enter all
desired parameters through a push button keypad unit and LCD display or connect via a
laptop. This approach allows the operator to define and configure the unit at the location
of operation, with minimum opportunity for error.
The Pole and Camera Housing
During on-site operation, the enforcement unit is usually housed in a protective
cabinet on top of a pole. There are several types of poles including fixed, hinged,
manual, and automatic lowering. Installation of a pole and cabinet includes the connection
of all necessary interfaces with the main power supply, subsurface loop detectors and
signal controller. These connections interface the unit with all other elements of the
highway-railroad intersection, including the main power supply, signal controller, and
subsurface loop detectors.
The camera enclosure should be constructed of a double wall of steel. The inner
cabinet should have welded joints that fully protect the unit from sabotage and adverse
weather. The outer plates serve as an added layer of protection, and provide ballistic
resistance and temperature modulation for the cabinet. The housing should be zinc dipped
to further protect the unit from corrosion and chemical wear. An enamel paint color
selected to blend in with the environment should be applied to the cabinet and baked to
produce a durable industrial quality finish. The two windows, in front of the camera and
flash, should be protected by optically correct bullet resistant glass. Access to the
cabinet should be controlled by a double steel plated hinged door with a locking
system. The key needed to operate the lock is of a unique design that is not available to
the general public.
Each cabinet should come pre-wired to accept all leads from the main power
supply, signal controller, and loop detectors. All connections are made at the time of
To help satisfy an agencies requirements for system accuracy, each unit should
be tested on an annual basis by an approved independent laboratory. These approved
laboratories currently certify traffic enforcement systems, including radar units, photo
radar systems and breathalyzer devices for law enforcement agencies. Upon successful
completion of the test, each unit is issued a certificate of calibration that can be
provided as part of the evidence submitted to a Traffic Court.
Data Block or Bar
Most systems used today have some method of recording on the same piece of film
that contains the image of a violation the data that are associated with the violation.
Arranged in a bar or block such items as date, time, location, frame, time since red phase
began, etc. are imprinted on the film using LEDs or other mechanism.
Building a photo-enforcement is a significant undertaking. The following
describes the processes and decisions that must made for a successful implementation.
Whether a jurisdiction decides to build in-house or contract the job out to one or several
vendors, these decisions will have must still be made. The following will describe
building a red-light system, but most of it is applicable to other photoenforcement
A red-light system is composed of several components, each of which requires
multiple decisions that will effect the overall cost and performance.
- Violation Detection and Capture
- Film Collection and processing
- Imaging Processing, Violator Identification, and Issuance
- Citizen Services
- Financial Collections
- Management Reporting
Each component requires different resources such as hardware, software, human,
and management. Decisions must be made, resources allocated, and training provided. In
addition, capital must be set aside to provide for the purchase and maintenance resource
The most observable feature of a red-light camera system is the camera. It is
the camera that almost all citizens will identify as "the program." Actually,
the term "camera" is misleading. The box that is often called the camera is
actually the housing, computer, data store, battery, flash unit, and the camera itself.
Decisions that are frequently related to violation detection often include:
||Frontal, Rear, Both
||Fixed, Folding, Manual Up-down, Electric up-down
|Detector Trigger Type:
||Loop, Pieazo, Earth magnetic, LASER
||Which intersections and which directions will be monitored
||Who will decide placement of loops cameras, etc.
|Live Intersection Monitoring:
Site engineering requires a thorough understanding of the detection
requirements. Camera selection, location, lanes monitored, trigger type, detector
location, and information required from the system must be designed into each
intersection. If possible, site engineers should have experience in standards intersection
management as well as automated enforcement systems.
The training of engineers and other staff who will be involved in the design of
the monitoring site should include thorough presentations of all technologies involved in
the system. One or two weeks of experience with each vendor is desirable. Vendor site
visits should be arranged so that the staff can gain first hand knowledge of the selected
system and also be able to discuss R&D, product renovation, and repair issues with the
individuals actually responsible.
When wet film is used, the exposed film must be recovered and replaced with
fresh film on a regular basis. Film is usually housed in a removable film cartridge. The
film cartridge - which may contain as many as 800 frames - is usually replaced daily.
Depending on the pole type selected, a bucket truck or ladder may be required. In addition
to exchanging film, the camera should receive inspection and servicing for damaged and
malfunctioning parts. Several test shots are usually made at the beginning of each roll of
film to verify correct operation.
After the film is collected, it must be processed in a film lab. The film lab
may also reload the film cartridges with fresh film. It is essential that the film lab
provide reliable, consistent, and quality-controlled service. The film lab should also
provide a report of any problems such as camera malfunction or misalignment.
|Type of Film
||Color, B&W, Speed
|Camera Serviced by:
||Truck, ladder, etc.
||Contract, Commercial, in-house
|Pick-up and Delivery Service
|Chain of Custody Record Process
Film obtained from red-light cameras is evidence of a civil or criminal act. As
such, it should be handled accordingly. A "Chain-of Custody" must be maintained
for the film. That is, a complete record of all individuals who handle the film must be
available to the courts in a timely manner should the need arise. Camera servicing
personnel should be bonded and should be possess the necessary skills to service the
cameras. Generally, film servicing occurs at night. Depending on the location of the
cameras, one individual can service up to eight cameras per shift.
Several agents should be trained to perform routine maintenance on the cameras
such as vandalism repair, replacement of lenses, electronic boards, etc. Agents should
also be trained to test the system after reloading the camera. Field service technicians
should receive at least two week of training in camera maintenance and repair.
Film review is the process by
which developed film is examined for violations. In this process, film frames can be
viewed and stored physically or electronically for future reference. Using
electronic storage enhances timely and remote access to images. Also at this time, a
citation may be generated and prepared for mailing. Identification of the vehicle and
owner can be obtained either manually, by entering the plate number into a DMV system and
copying the data returned into the citation record, or automatically using license plate
optical character recognition (OCR) software connected directly to DMV.
|Film Storage Site
|Include Images on Citations
|Video Capture Method
|Process Out-of-State Plates
|Process Rental Car Plates
|OCR Plate Recognition
||On-line, batch, tape, etc.
|Chain of Custody storage
This task should be performed by individuals with the following skills:
- Windows/GUI knowledge if used
- Good Vision
Assuming the above skills exist, a minimum of two days should be allowed for
In cases where a defendant wishes to contest a notice, jurisdictions are
obligated to provide hearings before a judge to resolve the issue. Hearings with the
defendant present are usually held in person but can occur by mail in some jurisdictions.
From a technology perspective, information regarding the hearing, information about the
defendant, and information about the offense including evidence must be made available to
the court. Regardless of whether the information is presented in a technological fashion
as with PCs or on paper, it is usually stored in a computer system. The
results of the hearing or trial must also be recorded and stored. The processes together
are referred to as adjudication. The components usually associated with adjudication are:
- Court facility scheduling
- Judgment including fine amount
Rules of Evidence
The admissibility of film has been well established in American jurisprudence
These rules are codified in Article X of the Federal Rules of Evidence.
Chain of Custody
For evidence to be admissible in a court of law, certain conditions must be met.
One of these is know as chain of custody.' This simply means that any material, e.g.
film, must be handled in such a way as to ensure that it is not altered, substituted, or
contaminated in any way. Requirement for chain of custody in photo-enforcement is usually
met with a log that tracks who have had possession of the recorded images and associated
data since the occurrence of the violation, and securing original film in limited access
areas to prevent tampering.
While the use of photo-enforcement now well established in the world outside the
United States, it is still being challenged in the U.S. Expert witnesses should be
available to testify to the soundness of the technology. In a discussion on the possible
legal challenges to photo technology, Lynn,
et al. Conclude:
Using the silent witness theory, photographic evidence is admissible if other
technical evidence relating to the smooth functioning of the camera is sufficient to
provide an adequate foundation assuring the accuracy of the process producing it
(Ferguson, 1972). This theory has been used to admit into evidence photographs
produced by Regiscope cameras, which are used to photograph check-cashing transactions
(Ferguson, 1972). Since the processes used by Regiscope cameras and photo radar are
analogous, it is possible that photo radar photographs produced by an unstaffed unit would
be admissible under the silent witness theory(Lynn, 1993).
First applied in the 1980s as the Paperless Office, an attempt
to reduce the amount of paper files has continued and is now being discussed as a way to
make courts more efficient. The nation witnessed the used of personal computers in the
courtroom during the infamous O.J. Simpson trial of 1995. Access to information in a
well-organized manner is now considered essential by most trial lawyers. However, even
Judge Ito was observed accessing information on a laptop during the trial.
Many courts now have docket and adjudication tracking systems in place. These
can be used as is or modified to incorporate photo enforced traffic laws. What
is relatively new, however, is online access to violation images rather than still photos.
Violation images can be stored in a database and made available to the courts the same as
other forms of data. The quality is good and evidentiary requirements are met.
||Yes / No
|Location of Courtroom(S)
|Source of Judges
||Yes / No
|Hearings by Mail
||Yes / No
Two full-time judges and clerks are usually required the volume of cases from
fifteen cameras. If administrative law judges are used (as in New York City), private
lawyers can be contracted on a part-time basis.
Training for clerks and judges should include the use of the computer system as
well as details of how red-light systems work.It is important for judges to understand the
conditions under which a red-light camera takes a picture. Clerks and judges need two days
of training to become familiar with the system.
Once a defendant has pleaded guilty, has been judged guilty by a court, or has a
default judgment against him or her, he or she may be required to pay a monetary fine.
Reporting and tracking collections of fines is a significant part of any automated law
enforcement program. Once a judgment is rendered by admission, court, or default
a fixed period of time is usually allowed for payment.
After the time period of the primary notice has expired, a default judgment may
be entered against the defendant. A notice to this effect may be sent. If this notice is
not responded to, a monetary penalty may be imposed. Additional action may be taken which
may include suspension of license or a block may be placed on registration of the motor
vehicle. In any case, the current status of the complaint must be maintained on the
database and appropriate actions taken based on business and legislative rules.. The
Noticing process is usually system generated. Generally, two subsequent noticing periods
are defined, usually thirty to forty-five days apart. Once a third notice has been issued
and a grace period has expired, the citation may be placed in "Default Judgment" status. A warrant may then be issued. Depending on local and state laws,
the agency may elect to:
- Assign account to collection attorney of sheriff
- Boot, tow, and sell the vehicle
- Seize non-exempt personal property
- Restrain bank account
- Garnish non-exempt wages
- Prevent renewal of motor vehicle registration
Second and third noticing usually consists of a form letter that contains the
owner or operator's name, address, citation number, issue date, violation date, plate
number, fine and penalty.
There are many ways to handle payments made for fines. Collection windows and
mail-in are the most common. But funds must ultimately be deposited in a financial
institution. This process can be subcontracted to a bank or other financial institution
whose primary function is processing receipts. In a typical Lockbox arrangement, payments
are mailed to a PO Box owned by a bank. The box is usually checked daily sometimes
several times a day -- and envelopes containing payments are processed and funds
deposited. Reports are made on paper and/or electronically which detail the
transactions made by the Lockbox agent. The Lockbox agent forwards letters and other
nonpayment items to the jurisdiction. Lockbox agents are usually paid on a per transaction
Updating Citation Databases
A database containing the records of each violation processed by a jurisdiction
must contain the current status of the notice and must reflect any payments made to the
fine. Partial payments and overpayments must also be tracked and a process for noticing
underpayments and returning overpayments must be in place.
Sound fiscal practice mandates that extensive records be kept and audited.
Reconciliation between database records and Lockbox receipts must be made on a regular
basis. If possible, reports generated by the processing system and by a Lockbox agent
should be reconciled daily. Some common reports from a Lockbox agent include:
Lockbox agents normally process checks, deposit them, and prepare written and/or
electronic reports. Electronic reports can be input to the system through modem or tape.
Written reports from the lockbox agent can be used to balance system reports on a daily
basis to insure accuracy.
The lockbox agent should be expected to provide the following reports:
- Detail of payments received
- Returned checks (NSF)
- Non-depositable checks (unsigned, etc.)
- Unapplied (insufficient information to process)
- Correspondence accompanying checks
- Deposit slips for items processed
The system should report the following information:
- Detail of payments applied including totals
- Record of transactions that could not be applied including totals
Experience by some jurisdictions indicate that as much as 70-80 percent of fines
are paid. Payments can be received in many ways, such as walk-up/drive-up windows, by
mail, or through third parties such as stores or banks.
While the entire system should be protected from inadvertent, malicious, or
criminal access, it is especially important that the financial system be protected.
Physical and electronic access to financial records should receive the highest security
|Data Transfer Method
||Modem, Tape, etc.
Lockbox and system reports should be sent to someone experienced in financial
practices. These reports should be checked daily and audited on a regular basis.
Employees should be trained to review reports and help resolve any
discrepancies. Two days of training are usually needed.
In 1991, The City of New York took a revolutionary position as a municipal
jurisdiction when it pioneered a pilot program to evaluate red-light camera monitoring
technology in the U.S. New York City currently has the largest operational system for
red-light enforcement. (Unless NYC expands its current program, San Francisco will surpass
it sometime next year.) Several other communities have also studied red-light
enforcement using photographic technology. In Florida, Haines City, Ft. Meade, and
Lakeland have had pilot programs. Many others such as Jackson, MI and have already tested
According to EDS, the Vendor
supporting New York City:
Due to a widespread disregard for traffic lights, crossing New
York Citys intersections can be a life-threatening act for pedestrians and drivers
alike. According to the citys Department of Transportation, five times more people
die in traffic crashes than in fires. And many of those deaths are caused by red-light
Catching the violators would be a double blessing: the city could
demonstrate its resolve to enforce the law; and the public would be safer. But short of
putting police officers at every intersection, how could red-light runners be identified
Based on the citys specifications, EDS developed and implemented a
system that provides proof few drivers can refute. Advanced traffic cameras are focused on
18 troublesome intersections. If a car runs the light, it triggers the camera, which snaps
two rear-angle photographs less than a second apart capturing the violation and license
Once the violation is verified by city employees, an EDS client/server
system captures the photographic image and prints a Notice of Liability bearing the
photos, which is then sent to the vehicles registered owner. It also enables the
city to schedule hearing dates, process fine payments and reconcile accounts. In addition,
it allows judges to view photographic images on courtroom computers.
In one year, the system helped New York City issue more than 168,000
notices and levy $6.7 million in fines. With a collection rate of more than 80 percent,
the city realized $5.4 million in revenue from fines. The programs total operating
costs, including the citys labor expense and EDS monthly fee, have been offset
by the monthly revenue brought in. But most important, red-light incidents decreased by
approximately 10 percent, making it safer to step off the curb.
Now that New York City has put the brakes on careless drivers, interest
in the approach has accelerated. People from all corners of the world are calling to learn
After its first year of operation, the vendor responsible for for installation
and operation of the New York Red Light Project (EDS) submitted a report to the City of
New York. This report was mandated by State law. The following is excerpted from that
New York City has an estimated 43,000 intersections, of which over 10,500
are controlled by traffic signals. However, it is estimated that the majority of red-light
violations occur at 300-400 of these intersections.
During the period 1981-1985, 13,240 pedestrians were killed or injured in
the U.S. while crossing with the signal. To this number must be added a large percentage
of the 388,176 motorists and bicyclists killed or injured due to red-light offenses.
According to an investigative report aired on CBS News in 1986, 1,000,000
red-light offenses occur in New York City every day. According to CBS and NYC/DOT,
400,000+ citations for red-light offenses were issued during the corresponding period.
The New York City Department of Transportation -- one of the largest
agencies in the state -- oversees the Parking Violations Bureau, the Bureau of Traffic,
and the citys transportation infrastructure. More than a million traffic violations
occur in the city each day. On average in the U.S., a pedestrian a day is killed by cars;
many of the deaths are caused by drivers who run red-lights. The department sought a way
to identify, apprehend and successfully prosecute red-light runners to enhance pedestrian
From November, 1991 to March, 1992 EDS conducted a New York City approved
limited on-site pilot program. During the 31 day active period, 1,085 citations were
issued resulting in $30,380 received in payment.
After this successful five month pilot in 1992, the City of New York
awarded EDS a six year contract (three base, plus three one-year options) to implement and
operate a system to photograph and issue traffic tickets to individuals who violate New
York State law by failing to stop at a red-light. A law was enacted to allow the city to
fine violators for running a red-light. This law has a sunset provision which currently
mandates an end date to this contract of December 14, 1996. The law also restricts camera
installations to a total of 25 intersections. The law also requires participating cities
to have a population of at least one million people.
On June 1, 1993, EDS and its business partners, LeMarquis and Mulvihill
Electric, began a forty-one-month contract, with three one-year options, to implement and
operate EDS Automated Law Enforcement System (ALES) for New York City using
red-light camera technology.
Red-light cameras are fully automated systems designed to photograph,
under any weather or light condition, vehicles in violation of a red traffic signal. The
initial purpose of the red-light camera is to provide, through sequential photographs,
indisputable evidence of red-light offenses. Similar cameras, used in over 40 countries
worldwide, are designed to supplement the police force and provide:
- Law Enforcement
The use of red-light cameras benefits the public as well as
municipalities. red-light cameras can be used only if appropriate legislation is enacted
enabling the registered owner to be held responsible for a violation committed with his
vehicle. In many respects the ticket generated is similar to a parking ticket.
On December 1, 1993 EDS implemented an automated system that photographs
red-light offenders, issues tickets to vehicle owners, and supports ticket processing.
State-of-the-art cameras and imaging technologies are two innovative features of the
system. Initially cameras have been installed and are active at fifteen (15) locations
throughout the five boroughs of New York City. On December 15, 1993, the system was
EDS Corporation (EDS)
Supplies project management, cameras, computers, and system processing.
LeMarquis International, Inc. (LMI)
Supplies cameras, flashes, film viewers, and spare parts. Supplies and
develops the film used in the project. LeMarquis is a business partner and provides
marketing services throughout the U.S.
Mulvihill Electrical Contracting Corp. (MECC)
Provides field construction of each site, daily camera maintenance and
daily film exchange.
The First Year of Operations
The following section summarizes the results of the first
twelve months of operation, January 01, 1994 through December 31, 1994.
1994 ANNUAL PROGRAM STATISTICS
Number of Events
Number of Usable Events
Percentage of Usable Events
Number of NOLs Generated
Violation Fines (NOLs x $40)
Many photographs do not result in a ticket even though they clearly
show the vehicle running a red-light. The contractor has no control over these occurrences
because they are dictated by either things beyond our control like weather, or the speed
of the car, or it is due to the Citys policy not to ticket vehicles such as those
with out-of-state plates, emergency vehicles, police vehicles, funeral processions, etc..
Here are some examples when an exception to generating a ticket will occur that is beyond
the Contractors control.
WEATHER: If the stop bar is covered with snow, a ticket will not be
CITY POLICY: If a plate is from out-of-state or is partially obscured by
mud, dirt etc., a ticket will not be issued.
SPEED OF THE VEHICLE: If a vehicle is traveling much faster than or much
slower than the speed limit, the vehicle cannot be ticketed in many cases because by the
time the camera takes the second required photo, the car could be either out of range
(traveling too fast), or it may still be in the crosswalk (traveling too slow).
Therefore, the measure of usable readable film produced by the cameras is
important to know. This figure represents the maximum percentage of tickets we could have
produced (i.e.: what the cameras are capable of).
The number of usable readable photographs produced in 1994 was 263,330.
This results in a percentage of usable film of 60%.
Events are defined as a pair of photographs evidencing a possible
violation of law. All events (i.e. film) are reviewed by city employees. They decide to
ticket or not ticket each pair of frames based on guidelines provided by the city. Not all
events become a ticket. Events can result in either an NOL being issued or an exception
being recorded. An exception is recorded if the viewer decides not to issue an NOL. All
frames of film are thus accounted for. The following is a list of the current exceptions
to issuing a ticket. Many of the reasons are beyond the control of the contractor, but
some are directly controlled by the actions of the contractor, and thusly, the percentage
of NOLs produced each year is greatly affected by the actions of all three business
As the chart indicates, monthly volumes of events captured fluctuates.
This can be due to a variety of reasons such as the number of days in a month, camera
malfunctions, traffic patterns due to detours, or simply due to increased public awareness
of the locations.
Notice of Liability (NOL) Issuance
The following represents the highlights of the first year.
# of active cameras: 15 (3 additional cameras, for a
total of 18 active, were added effective 12/15/94)
# of NOLs: 168,471
Average daily NOLs: 462
Average daily NOLs per site: 31
NOLs as a percentage of events: 38%
Violation Fine Activity
Total Fines Generated: $6,738,840
Monthly Average Generated: $ 561,570
Total Payments Received During 1994: $5,435,815
Monthly Average Received: $ 452,985
Total hearings: 8,056
Average # of hearings per month: 671
Percent guilty: 86%
Automated cameras placed at fifteen
locations (18 as of 12-15-94) in the five boroughs of New York City capture red-light
violators on 35mm, 50ASA, B&W photographic film. The cameras are computerized and
record date, time, and location on each frame. The cameras are tied directly to the
traffic signal system and are active only during the red phase of the traffic signal
A pair of electromagnetic induction loops are embedded in the crosswalk
area of each lane to be monitored. These serve as the triggering mechanism for the
red-light camera. The red-light camera is connected to the loops and to the red phase in
the traffic signal pole. During the green phase of the traffic signal cycle, the unit is
deactivated and photographs can not be taken. During the amber phase the unit is
automatically switched to stand-by, and with the start of the red phase the camera is
activated after an initial .3 second delay.
When a vehicle passes over the loops during the red phase, the first
photograph is taken documenting on the film the traffic light in the red phase, the
vehicle prior to the crosswalk, and a number of supportive data in a data field across the
top of the picture. A second photograph is taken within a predetermined time frame
(currently .5 - 1 second) documenting the vehicles position in the intersection.
The film is collected and processed by an EDS team member and delivered
Any change to the system or the cameras is documented and presented to
the city for approval. Keys to the camera housings have been given to the city to allow
inspection of any cameras and / or intersections at anytime the city desires.
As delivered and installed, the fifteen cameras worked well, and the
system was successful in producing a much greater than anticipated conviction rate that
translated into receipt of more revenues than expected. However, as the statistics
indicate, we were only able to write tickets on 38% of the events captured. As stated
before, this is due to a multitude of reasons and is depicted in the following table.
MOST SIGNIFICANT REASONS WHY TICKETS ARE NOT ISSUED
Nine film viewers (actually Sony video cameras mounted on a small
film transport platform) are connected to PCs via a graphics card. This allows operators
to capture images from film. Three images showing the vehicle prior to the intersection,
in the intersection, and a close-up of the plate are captured and printed on the citation
(NOL). Data and images are stored in a database on a mini-computer.
Help Desk and Judges
Four help desk PCs are provided to allow the scheduling of hearings and
the reprinting of tickets. In addition, the Help Desk staff processes walk-in payments and
handles a large number of inquiries from violators.
NYC provided two courtrooms for the adjudication of red-light NOLs. Two
PCs are provided for this judicial process. Each PC used in a courtroom has two 17"
monitors. Operated by a clerk, the defendant and judge view one monitor while the clerk
views another. Both images are the same. The clerk has the ability display any of the
three images full screen. Results of the hearing are then keyed by the clerk.
The New York Red Light Account operates the EDS Automated Law Enforcement
System (ALES), a client/server image-based computer system. A peer-to-peer enterprise
network connects the Bureau of Traffic in Queens and Parking Violations Bureau in
Manhattan with a T1 circuit.
First Year Summary
After one full year of operation, it is apparent that the City achieved
its objectives to identify, apprehend, and successfully prosecute red-light runners to
enhance public safety. Statistically, the public has been identified with increased
voluntary motorist compliance with the traffic control law as evidenced by a substantial
reduction in incidents reported per intersection. All of this was accomplished while
meeting the financial objective of having the violators pay for the program, rather than
using tax dollars to underwrite costs.
Efforts are underway to expand the number of cameras available to monitor
intersections, to a level that will be twice the number used at the beginning of the
program. Other expansion areas may include additional hearing and help line sites,
automated interfaces, ad hoc reporting, decision support analysis, traffic flow
monitoring, and correspondence imaging.
This New York Red Light Vehicle Monitoring program clearly illustrates
how a city can increase safety of their citizens at the expense of law breakers.
After six years of operation, the NYC red light program
is a model for US cities. Recently, the City issued an RFP for an expanded
program requiring new hardware. Two bidders made the final cut, and a
decision is expected soon as to which group will install a new red light
camera system. The finalists were EDS and Mulvihill Electric. Both of the
companies participated in the first six-year program.
Three Polk County, FL evaluated red-light camera systems: Fort Meade, Haines
City, and Lakeland. Currently, no legislation permitting photo-enforcement has been
enacted. The primary contractor for Fort Meade and Lakeland was ATS. The cities each sent 100-300 warning letters per
month during the pilots.
Originally, Polk County had not planned to disclose the presence of the
red-light systems, but the media discovered the programs and responded negatively. Road
signs were subsequently added advising drivers of the program.
A red-light camera pilot was begun in August of 1992 in Jackson, Michigan using
one camera with two housings. The program issued about ten warning notices per month.
Unlike Polk County, FL, Jackson was concerned about the possibility of negative
public reaction to the system. The city placed several articles in a local newspaper.
Eight months after the system had been installed and several hundred notices had been
sent, the city had received virtually no public objections.
A 30 day pilot program in 1989 was discontinued due to technical problems. The
problems were subsequently resolved and the pilot continued.
A research project sponsored by the Insurance Institute for Highway Safety has
been in operation since 1993 at one intersection. The project is supported by many
unaffiliated property and casualty insurance companies for the purpose of studying trends
in red-light violations such as weather, traffic, time of day, and types of vehicles. Such
research aids in the creation of policy for the Institute and its members.
Information collected from photo-enforcement vendors is located on the Products page of this site.
Over the past several decades, increasing traffic volumes worldwide have placed
greater demands on infrastructures while dramatically increasing the number of traffic
accidents and fatalities. The ease of administering automated red-light camera enforcement
has significantly improved from the days of August, 1983, when the Victoria, Australia
system required four weeks to issue an infringement notice. Today, automated red-light
systems are installed in over 45 countries including Germany, Great Britain, Hong Kong,
Malaysia, the Netherlands, Singapore, Switzerland, and Australia.
In the United States, an increasing interest in photo-enforcement has led to the
implementations of pilot programs of red-light cameras. Since the technology has been
successfully used worldwide for over forty years, the primary purpose of pilot programs
seems to be for jurisdictions to test the political waters before committing to community
Active Enforcement Locations
Information about the implementaion of red-light systems in the US can be found
on the Locations page of this site.
For additional information please see these web sites:
red-light and speed program
Tempe. AZ red-light
and speed program