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 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 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.
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.
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
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
Britain.
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=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.
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.
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.
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.
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.
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
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
- 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
- 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.
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.