2. INTRODUCTION
Although there is good road safety performance, yet the
numbers of people killed and injured on our roads
remain unacceptably high. The main reason is excess
speed of vehicles. We use traffic lights and other traffic
managers to reduce the speed. One among them is
speed cameras.
Speed cameras on the side of urban and rural roads are
usually placed to catch transgressors of the stipulated
speed limit for that road. Laws are passed making
excessive speed an offence. The speed cameras are used
to identify those drivers that pass by them when they
exceed the stipulated speed limit
3. WHAT IS A TRAFFIC
ENFORCEMENTCAMERA
A traffic enforcement camera (also red light
camera, road safety camera, road rule camera,
photo radar, photo enforcement, speed camera,
Gatso) is an automated ticketing machine. It may
include a camera which may be mounted beside
or over a road or installed in an enforcement
vehicle to detect traffic regulation violations,
including excess speed, vehicles going through a
red traffic light, unauthorized use of a bus lane,
for recording vehicles inside a congestion charge
area.
5. HISTORY
The concept of the speed camera can
be dated back to at least 1905; Popular
Mechanics reports on a patent for a
"Time Recording Camera for Trapping
Motorists" that enabled the operator to
take time-stamped images of a vehicle
moving across the start and endpoints of
a measured section of road. The
timestamps enabled the speed to be
calculated, and the photo enabled
identification of the driver.
7. TRAFFIC ENFORCEMENT
CAMERAS
Fixed-speed and red light cameras
With the introduction of digital technology, it is becoming
more common for red-light cameras to also function as
fixed speed cameras. Most red-light cameras and many
speed cameras are fixed-site systems mounted in boxes or
on poles beside the road. They are also often attached to
gantries over the road, or to overpasses or bridges.
Mobile Speed Cameras
Mobile speed cameras may be hand-held, tripod mounted,
or vehicle-mounted. In vehicle-mounted systems, detection
equipment and cameras can be mounted to the vehicle
itself, or simply tripod mounted inside the vehicle and
deployed out a window or door.
Bus lane enforcement cameras
Stop sign enforcement cameras
8. Fixed camera systems can be mounted in boxes or on
poles beside the road or attached to gantries over the
road, or bridges. Cameras can be concealed or dazzled
9. TRAFFIC ENFORCEMENT
CAMERA SYSTEM
AVERAGE SPEED CAMERAS SYSTEM
These systems operate using automatic digital technology. The
video cameras continuously capture images of vehicles. The
number plates are read using Automatic Number Plate Recognition
(ANPR) and the average speed of the vehicle is calculated between
the two cameras. If this exceeds the speed limit, an offence record
is created.
How average speed camera systems works
Average speed camera systems work by calculating the speed of a
vehicle over a distance. A vehicle enters the gateway and the
camera using Automatic Number Plate Recognition (ANPR) records
the number plate. When the vehicle passes through the exit
gateway the camera matches the number plate and carries out a
simple time over distance calculation and if the vehicle has been
travelling above the speed limit the offence is recorded. If there is no
offence, the camera does not retain details of the vehicle number
plates. Below is a diagram illustrating how an average speed
camera system works.
11. Why we use an average speed camera
system
Average speed cameras help to make roads safer by
encouraging drivers to maintain a consistent speed
limit.
Average Speed Cameras are one example of new
Intelligent Transport Systems (ITS). The information
collected by the cameras is used to make our roads
safer.
Roadwork’s can prove a dangerous working
environment for contractors, with drivers having to
react to contra flows, narrow lanes and changes in
road layout. The operational safety of the site is
enhanced when speed limits are reduced.
The average speed camera system has been
installed to ensure compliance with the reduced
temporary 40mph speed limit. The speed limit has
been reduced for the safety of the construction worker
and all road users. A positive effect of average speed
12. ANPR
The Automatic Number Plate Recognition (ANPR) is a fixed or
mobile speed camera system that measure the time taken by a
vehicle to travel between two or more fairly distant sites (from several
hundred meters to several hundred kilometers apart). The name
derives from the fact that the technology uses infrared cameras
linked to a computer to "read" a vehicle's registration number and
identify it in real-time.
Technology used in ANPR
ANPR uses optical character recognition (OCR) on images taken by
cameras. One of the changes made was to the font, introducing small gaps
in some letters (such as P and R) to make them more distinct and therefore
more legible to such systems, as shown below
13. Avoidance/evasion
Drive at or below the legal speed
Brake just before a camera in order to travel past its
sensor below the speed limit. This is however a cause of
collisions.
Use GPS navigation devices which contain databases of
known camera locations to alert them in advance. These
databases may in some cases be updated in near real-
time. The use of GPS devices to locate speed cameras
is illegal in some jurisdictions.
Install passive laser detectors or radar detectors that
detect when the vehicle's speed is being monitored and
warn the driver. Use of these devices may be illegal in
some jurisdictions.
Install active laser jammer or radar jammer devices
which actively transmit signals that interfere with the
14. CONCLUSION AND FUTURE WORK
I have presented a model-based vehicle
tracking and classification system
capable of working robustly under most
circumstances. The system is general
enough to be capable of detecting,
tracking and classifying vehicles while
requiring only minimal scene-specific
knowledge.