TIRTL
Encyclopedia
Speed sensor
Speed sensors are machines used to detect the speed of an object, usually a transport vehicle. They include:*Wheel speed sensors*Speedometers*Pitometer logs*Pitot tubes*Airspeed indicators*Piezo sensors *LIDAR*Doppler radar...
, red light camera
Red light camera
A red light camera is a traffic enforcement camera that captures an image of a vehicle which has entered an intersection against a red traffic light. By automatically photographing vehicles that run red lights, the camera produces evidence that assists authorities in their enforcement of traffic laws...
sensor, heavy vehicle tracker, overheight vehicle sensor, rail crossing sensor and network management system. The initial development of the device started in 1997 in conjunction with the New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
Roads and Traffic Authority
Roads and Traffic Authority
The Roads and Traffic Authority is a former New South Wales government agency that was responsible for major road infrastructure, licensing of drivers, and registration of motor vehicles. The RTA directly managed State roads and provided funding to local councils for regional and local roads...
& started commercial domestic and international sales in 2002. It is currently in use in sixteen countries.
It uses infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
light cones sent from a transmitter to a receiver situated on opposite sides of the road perpendicular
Perpendicular
In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...
to the flow of traffic. It has the ability to classify, record speed, and record volume for motor vehicles. The unit's data logging capabilities are enhanced by several flexible options for output. These options allow for real time applications, such as variable message sign
Variable message sign
A variable- message sign, often abbreviated VMS, CMS, or DMS, and in the UK known as a matrix sign,...
triggering and traffic enforcement, as well as data logging for statistical purposes.
Overview
TIRTL is an acronym for The Infra-Red Traffic Logger. It is manufactured by CEOS Pty Ltd, and marketed by CEOS Industrial. The device was initially developed in 1997 in conjunction with the New South WalesNew South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
Roads and Traffic Authority
Roads and Traffic Authority
The Roads and Traffic Authority is a former New South Wales government agency that was responsible for major road infrastructure, licensing of drivers, and registration of motor vehicles. The RTA directly managed State roads and provided funding to local councils for regional and local roads...
, before the company received a grant from the Government of Australia
Government of Australia
The Commonwealth of Australia is a federal constitutional monarchy under a parliamentary democracy. The Commonwealth of Australia was formed in 1901 as a result of an agreement among six self-governing British colonies, which became the six states...
in 1998 to develop it further before commercial sales started in 2002. It is currently in use in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Luxembourg
Luxembourg
Luxembourg , officially the Grand Duchy of Luxembourg , is a landlocked country in western Europe, bordered by Belgium, France, and Germany. It has two principal regions: the Oesling in the North as part of the Ardennes massif, and the Gutland in the south...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...
, India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
, Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
, the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
. The device is currently in its third generation.
It has the ability to record volume, speed, and classification on a bi-directional, multi-lane roadway. Primary applications for this device include speed verification for enforcement purposes, traffic volume and density data collection for both statistical and real time usage, and vehicle classification by axle spacing. The device is usable in both portable and fixed applications, due to its communication capabilities and rugged enclosure. The unit was originally developed to provide secondary verification for intersection safety cameras deployed in the State of Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
, Australia. It was first deployed in Australia in July 1998. The unit was introduced to the North American market during the 2004 North American Travel Monitoring Exhibition and Conference (NAMTEC), and was first deployed in May 2006.
Detection Method
This system consists of a receiver unit and transmitterTransmitter
In electronics and telecommunications a transmitter or radio transmitter is an electronic device which, with the aid of an antenna, produces radio waves. The transmitter itself generates a radio frequency alternating current, which is applied to the antenna. When excited by this alternating...
unit placed on opposite sides of the road perpendicular
Perpendicular
In geometry, two lines or planes are considered perpendicular to each other if they form congruent adjacent angles . The term may be used as a noun or adjective...
to the direction of travel. The transmitter sends two cones of infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
light across the roadway, and the receiver records vehicles as they break and remake these cones. TIRTL transmitter's infrared cones cross each other and form two straight and two diagonal beam
Light beam
A light beam or beam of light is a narrow projection of light energy radiating from a source into a beam. Sunlight is a natural example of a light beam when filtered through various mediums...
pathways. When a vehicle crosses the beam pathways, TIRTL records two beam events; it records one from the vehicle breaking and one leaving the beam pathway. These two beams events are recorded for all four beam pathways. Thus, eight timestamp
Timestamp
A timestamp is a sequence of characters, denoting the date or time at which a certain event occurred. A timestamp is the time at which an event is recorded by a computer, not the time of the event itself...
ed events are generated per axle. The velocity is derived from the timestamps of these beam events.
Since the velocity of each vehicle wheel is known and a timestamp is recorded for each axle crossing each beam, the interwheel (or interaxle) spacings can be determined. Once the interaxle spacings are known, it is compared to a table of interaxle spacing ranges stored in the unit to determine the correct classification of the vehicle. The results are stored on a per vehicle basis.
Classification
The unit has a single-board computerSingle-board computer
A single-board computer is a complete computer built on a single circuit board, with microprocessor, memory, input/output and other features required of a functional computer. Unlike a typical personal computer, an SBC may not include slots into which accessory cards may be plugged...
running Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
. The computer interprets the supplied traffic classification table (Federal Highway Administration
Federal Highway Administration
The Federal Highway Administration is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two "programs," the Federal-aid Highway Program and the Federal Lands Highway Program...
Scheme F, or user supplied) and composes the axle events caused by the parallel beam breaks into a classified vehicle. The classification data is stored in the unit and can optionally can be streamed
Streaming media
Streaming media is multimedia that is constantly received by and presented to an end-user while being delivered by a streaming provider.The term "presented" is used in this article in a general sense that includes audio or video playback. The name refers to the delivery method of the medium rather...
in real-time
Real-time computing
In computer science, real-time computing , or reactive computing, is the study of hardware and software systems that are subject to a "real-time constraint"— e.g. operational deadlines from event to system response. Real-time programs must guarantee response within strict time constraints...
via a serial or an Ethernet connection. The raw beam event information can also be saved to the unit for verification purposes. The data is output as plain text
Plain text
In computing, plain text is the contents of an ordinary sequential file readable as textual material without much processing, usually opposed to formatted text....
. Thus, it can be translated to many common file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
s used in traffic data collection.
Features
The devices has two RS232 ports for data transfer. There are optional inbuilt GSM, PSTN, and satellite phoneSatellite phone
A satellite telephone, satellite phone, or satphone is a type of mobile phone that connects to orbiting satellites instead of terrestrial cell sites...
modems available. The unit has the ability to stream traffic information real-time which can drive intelligent traffic signs and send data back to traffic operation centers. There are also adapters available for connection to traffic camera
Traffic camera
A traffic camera is a video camera which observes vehicular traffic on a road. Typically, these are put along major roads such as highways, freeways, motorways, autoroutes and expressways, as well as arterial roads, and are connected with optical fibers buried alongside or even under the road,...
s for enforcement purposes.
Studies and approvals
- The Australian National Measurement Institute tested the accuracy of the vehicle velocity measurement. They found that there was a 1% deviation at 156 miles per hour (251.1 km/h).
- TIRTL was reviewed by the Minnesota Department of TransportationMinnesota Department of TransportationThe Minnesota Department of Transportation oversees transportation by land, water, and air in the U.S. state of Minnesota. The cabinet-level agency is responsible for maintaining the state's trunk highway system The Minnesota Department of Transportation (Mn/DOT, pronounced "min-dot") oversees...
. In conjunction with 16 participating state departments of transportation, they conducted a pooled fund study called Portable Non-Intrusive Traffic Detection System (PNITDS). The final report stated that TIRTL correctly classified 94% and 97% of the total vehicles polled.
- TIRTL is under review by the Hawaii Department of TransportationHawaii Department of TransportationThe Hawaii Department of Transportation is a state government organization which oversees transportation in the U.S. state of Hawaii. The agency is divided into three divisions dealing with aviation, maritime, and roads.-Airports Division:...
for use as the chief sensor in their traffic monitoring system. The system is in competition with other non-intrusive traffic collection devices.
- In November 2008, the state of New South WalesNew South WalesNew South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
, Australia, approved the device for use as a sensor for speed measurement.
See also
- Road traffic control
- Traffic counter
- Road speed limit enforcement in Australia
External links
- Official website in the US
- Manufacturer's website
- The Federal Highway Administration's Transportation Pool Fund Program website
- Minnesota Department of Transportation's Guidestar program, the umbrella project under which the PNITDS project was undertaken.