Red-Light
Home Up HOV Rail Plate Recognition Red-Light Speed Toll Road

 

Running a Red-light is a SNAP!®mc-camhead.jpg (5211 bytes)

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, 1995).

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 red-light."

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, 1995)

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 the law."

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 of compliers.

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

THE 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 around."

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 RUNNING

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?

VCU/SRL METROPOLL 1
DEPARTMENT OF MOTOR VEHICLES MODULE
When driving what moving violations do you see?
  Richmond
City
Chesterfield
County
Henrico
County
Hanover
County
Metro
Area
Total
Drunk or drugged driving 3% 5% 6% 4% 4%
Speeding 55% 65% 66% 62% 62%
No full stop at sign 26% 15% 21% 21% 21%
Illegal turns 11% 11% 16% 4% 12%
Tailgating 8% 14% 14% 24% 13%
Failure to signal turn 31% 21% 26% 19% 25%
Reckless driving 17% 14% 14% 15% 15%
Running red light 40% 35% 33% 27% 35%
Other 20% 18% 31% 26% 24%
None 2% 2% 2% 3% 2%

All percentages are weighed percentages.
Sampling error for questions answered by ALL respondents is approximately +/- 4%
Sampling error for subpopulations will vary and are higher than that for the full sample.

VCU/SRL METROPOLL 1
DEPARTMENT OF MOTOR VEHICLES MODULE
RED LIGHT RUNNING QUESTIONS
  Richmond
City
Chesterfield
County
Henrico
County
Hanover
County
Metro
Area
Total
Definition:
Enter intersection on yellow/turns red 25% 29% 23% 33% 26%
Enter intersection on red 69% 64% 70% 63% 67%
Other 6% 3% 4% 3% 4%
Don't Know 0% 4% 2% 0% 2%
How often do you see others run red lights?
Every day 35% 25% 27% 15% 27%
A few times a week 30% 29% 31% 43% 31%
A few times a month 17% 23% 19% 18% 20%
Less than once a month 14% 19% 18% 17% 17%
Don't Know 4% 4% 5% 3% 4%
Have you ever run a red light as you described it?
Yes, once 10% 12% 15% 12% 12%
Yes, a few times 30% 31% 33% 33% 32%
Yes, many times 5% 5% 2% 1% 4%
No 52% 51% 48% 53% 50%
Don't Know 2% 1% 1% 1% 2%

All percentages are weighed percentages.
Sampling error for questions answered by ALL respondents is approximately +/- 4%
Sampling error for subpopulations will vary and are higher than that for the full sample.

VCU/SRL METROPOLL 1
DEPARTMENT OF MOTOR VEHICLES MODULE
RED LIGHT RUNNING: CONSEQUENCES QUESTIONS
  Richmond
City
Chesterfield
County
Henrico
County
Hanover
County
Metro
Area
Total
Have you ever seen someone
ticketed for running a red light?
Yes 29% 30% 30% 23% 29%
No 65% 65% 68% 74% 67%
Seen someone ticketed near
light/Don't know why
6% 4% 1% 3% 4%
Don't Know 0% 1% 1% 0% 1%
How many out of 100 do you think will be ticketed?
0-10 55% 64% 62% 52% 59%
11-25 10% 7% 12% 10% 10%
26-50 10% 7% 5% 2% 7%
51 or More 4% 4% 1% 2% 3%
Don't Know 21% 17% 21% 33% 21%
How many out of 100 do you think will lead to crashes?
0-10 42% 51% 47% 55% 48%
11-25 14% 14% 18% 6% 14%
26-50 17% 12% 9% 8% 12%
51 or More 7% 6% 4% 0% 5%
Don't Know 20% 16% 22% 28% 21%

All percentages are weighed percentages.
Sampling error for questions answered by ALL respondents is approximately +/- 4%
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 this effort?

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 initiative?

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 national implementation?

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 nationally.

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 applicants.

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 campaigns.

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 programs.

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:

(202) 366-6902
FAX: (202) 366-2249
E-Mail:

 

Red-light Camera Systems

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:

  • Safety
  • Law Enforcement
  • Deterrence
  • Revenue

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 vehicle.

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 City’s fifteen red-light cameras. (A total of 295,414 red-light tickets were issued by the entire NYPD in 1993.)

Warrants for a Red-light Camera System

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 camera System.

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 public perception.
Traffic Volumes
What volume of vehicles traverse the intersection from each direction?
The greater the volume, the greater the likelihood of violations.
Speeds
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 readily available?
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.

Build or Buy?

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:

  1. Build in-house
  2. Use systems integrator
  3. Use systems manager
  4. Use outsource or process management company

The decision to "build or buy" should be made carefully.

Red-light Camera Technology

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.

How a Red-Light Violation is Captured

Automated 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 vehicle’s 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 vehicle’s 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.)
  • Vandalism

Red-light camera systems are usually composed of three main subsystems:

  • Camera
  • Control mechanism
  • Violation Detection

Red-light Cameras

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.

Red-light Camera Control

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.

Violation Detection

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 Britain.

TRIGGERS

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.

AIR TUBES

Mitron.gif (252495 bytes)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.

INDUCTIVE LOOPS

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.

loopwire.GIF (5214 bytes)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=lc*Lu
 
Where:
Lc=Inductance of lead-in Cable (uh)
lc=Length of lead in Cable
Lu=Unit inductance (uh/ft)
 
L=P/4(N²+N)
 
Where:
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. 

How Stuff Works
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Question 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!

Question    

How does a traffic light detect that a car has pulled up and is waiting for the light to change?

Answer

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 obvious.

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:

 

Loop Testing

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.

EARTH MAGNETIC LOOP

canoga.jpg (30888 bytes)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.

PIEZOELECTRIC STRIPS

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.

VIDEO LOOPS

A recent 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 cameras.

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 1).

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
  • Programmable
  • 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.

LASER

 

 

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 DSS:

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.

Installing a Red-light Camera System

As discussed above there are many factors to be considered in installing a red-light camera system. To summarize the steps:

  1. Review the laws regulating photo-enforcement
  2. Determine the need using the warrants listed above.
  3. Solicit community support for photo-enforcement
  4. Select a camera vendor and/or systems integration company
  5. Select probable locations
  6. Evaluate these location using a device such as the Mitron® Traffic Counter
  7. 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 CCD.
  • 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
  1. Construct site
  2. Test system
  3. . 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.

Citizen Services

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
  • Correspondence
  • 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 jurisdiction’s operational structure.

Help Desk

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.

Scheduling

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

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.

Information Access

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.

Decision

Options

Location of employees  
Phone hours  
Reprint Citations on demand Yes, No
Payment services Yes, No, Credit card
Automated voice response Yes, No
Staffing

Considering the assumptions given above, five to six employees are required to perform functions in conjunction with other help desk duties.

Training

Public relations, PC keyboarding, and MS windows or other GUI training is required. Two to four days of training should be sufficient.

Photo-Enforcement Violation Capture Equipment Requirements

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

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 Cabinet

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 initial installation.

System Calibration

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.

Construction Decisions

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 systems.

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
  • Noticing
  • Citizen Services
  • Financial Collections
  • Adjudication
  • 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 requirements.

Violation Detection

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:

Decision

Options

Camera Position: Frontal, Rear, Both
Camera Brand:  
Pole Type: Fixed, Folding, Manual Up-down, Electric up-down
Detector Trigger Type: Loop, Pieazo, Earth magnetic, LASER
Intersections: Which intersections and which directions will be monitored
Intersection Engineering: Who will decide placement of loops cameras, etc.
Live Intersection Monitoring: Yes, No:
Staffing

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.

Training

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.

Film Processing and Processing

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.

Decision

Option

Type of Film  Color, B&W, Speed
Camera Serviced by:  
Service Equipment: Truck, ladder, etc.
Film Lab: Contract, Commercial, in-house
Pick-up and Delivery Service  
Chain of Custody Record Process  
Staffing

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.

Training

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.

Imaging Processing, Violator Identification, Issuance

Citation Issuing.bmp (100485 bytes)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.

 

 

 

 

Decision

Options

Issuing Agency  
Processing Locations  
Film Storage Site  
Include Images on Citations Yes, No
Server/Workstation  
Video Capture Method  
Network  
Power Requirements  
Process Out-of-State Plates Yes, No
Process Rental Car Plates Yes, No
OCR Plate Recognition Yes, No
DMV Link On-line, batch, tape, etc.
Chain of Custody storage  
Mailroom Functions  
Staffing

This task should be performed by individuals with the following skills:

  • Typing
  • Keyboarding
  • Windows/GUI knowledge if used
  • Good Vision
Training

Assuming the above skills exist, a minimum of two days should be allowed for application training.

Adjudication

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:

Hearing scheduling

  • Court facility scheduling
  • Plea
  • Judgment including fine amount

Definitions

Rules of Evidence

The admissibility of film has been well established in American jurisprudence since 1859.

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.

Expert Witnesses

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).

Paperless Courtroom

First applied in the 1980’s 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