![Cycle counter](https://upload.wikimedia.org/wikipedia/commons/f/f9/Cycle_counter.jpg)
A traffic count is a count of vehicular or pedestrian
traffic
Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation.
Traffic laws govern and regulate traffic, while rules of the road include traffic ...
, which is conducted along a particular
road
A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation.
There are many types of ...
, path, or
intersection. A traffic count is commonly undertaken either automatically (with the installation of a temporary or permanent electronic traffic recording device), or manually by observers who visually count and record traffic on a hand-held electronic device or tally sheet. Traffic counts can be used by local councils to identify which routes are used most, and to either improve that road or provide an alternative if there is an excessive amount of traffic. Also, some
geography fieldwork involves a traffic count. Traffic counts provide the source data used to calculate the
Annual Average Daily Traffic
Annual average daily traffic, abbreviated AADT, is a measure used primarily in transportation planning, transportation engineering and retail location selection. Traditionally, it is the total volume of vehicle traffic of a highway or road for a y ...
(AADT), which is the common indicator used to represent traffic volume. Traffic counts are useful for comparing two or more roads, and can also be used alongside other methods to find out where the central business district (
CBD) of a settlement is located. Traffic counts that include speeds are used in
speed limit enforcement
Speed limits are enforced on most public roadways by authorities, with the purpose to improve driver compliance with speed limits. Methods used include roadside speed traps set up and operated by the police and automated roadside 'speed camera' ...
efforts, highlighting peak speeding periods to optimise speed camera use and educational efforts.
Counting methods
![Journey 2 110520 gnangarra-105](https://upload.wikimedia.org/wikipedia/commons/6/6a/Journey_2_110520_gnangarra-105.jpg)
To permanently or temporarily monitor the usage of a road, an electronic traffic counter can be installed or placed to measure road usage continuously or for a short period of time. Most modern equipment called ATR's (Automatic Traffic Recorders) store count and/or classification data recorded in memory in a
timestamp
A timestamp is a sequence of characters or encoded information identifying when a certain event occurred, usually giving date and time of day, sometimes accurate to a small fraction of a second. Timestamps do not have to be based on some absolut ...
or interval fashion that can be downloaded and viewed in software or via a count display on some equipment. In some instances people either draw up a table and/or use a
tally to keep a record of vehicles which pass manually as an alternative to ATR's.
Traffic counter devices
![Pole-mount video camera unit for traffic pattern analysis](https://upload.wikimedia.org/wikipedia/commons/c/c8/Pole-mount_video_camera_unit_for_traffic_pattern_analysis.jpg)
A traffic counter is a device, often electronic in nature, used to count, classify, and/or measure the speed of vehicular
traffic
Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation.
Traffic laws govern and regulate traffic, while rules of the road include traffic ...
passing along a given roadway. The device is usually deployed in near proximity to the roadway and uses an on-road medium, such as
pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...
road tubes laid across the roadway,
piezo-electric
Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied mechanical stress. The word ''p ...
sensors embedded in the roadway,
inductive loops cut into the roadway, or a combination of these to detect the passing vehicles.
Pneumatic
Pneumatics (from Greek ‘wind, breath’) is a branch of engineering that makes use of gas or pressurized air.
Pneumatic systems used in Industrial sector, industry are commonly powered by compressed air or compressed inert gases. A central ...
road tubes are generally used for temporary studies to study a sample of traffic, while
piezo-electric
Piezoelectricity (, ) is the electric charge that accumulates in certain solid materials—such as crystals, certain ceramics, and biological matter such as bone, DNA, and various proteins—in response to applied mechanical stress. The word ''p ...
sensors and
inductive loops are used for permanent studies which can ascertain seasonal traffic trends and are often used in congestion monitoring on major roads. One of the first traffic counting units, called traffic recorders, was introduced in 1937, operated off a strip laid across the street, and used a six volt battery. Each hour it printed off a paper strip with the total for that hour. A newer type of temporary sensor consists of a
metal detector
A metal detector is an instrument that detects the nearby presence of metal. Metal detectors are useful for finding metal objects on the surface, underground, and under water. The unit itself, consist of a control box, and an adjustable shaft, ...
and data recorder in a single package, adhered to the pavement in the center of a driving lane, unlike the pneumatic tube detector which cannot differentiate between lanes.
Recently, off-road technologies have been developed. These devices generally use some sort of transmitted energy such as
radar
Radar is a detection system that uses radio waves to determine the distance (''ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, w ...
waves or
infrared
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...
beams to detect vehicles passing over the roadway. These methods are generally employed where vehicle speeds and volume are required without classification which require on-road sensors. Other off-road technologies are video image detection systems. A portable digital camera unit can be mounted to a pole and
computer vision
Computer vision is an interdisciplinary scientific field that deals with how computers can gain high-level understanding from digital images or videos. From the perspective of engineering, it seeks to understand and automate tasks that the hum ...
software is used to analyze traffic pattern including traffic counts.
Bicycle and pedestrian traffic counting devices
Technologies for counting bicycles on roads, or bicycles and pedestrians along sidewalks or
shared-use paths have progressed with the increased emphasis on the economic, environmental and social benefits of multi-modal traffic networks. Non-motorized modes of traffic are often surveyed using the same types of sensors used for motorized vehicles; in some cases tuned to be more sensitive to actuation (e.g. Pneumatic tubes, Piezoelectric, inductive loop detectors, Passive and Active Infrared, Video, Magnetometers, et al.).
In 2004, the American private-sector firm Alta Planning and Design, in partnership with the
Institute of Transportation Engineers
The Institute of Transportation Engineers (ITE) is an international educational and scientific association of transportation professionals who are responsible for meeting mobility and safety needs. ITE facilitates the application of technology and ...
(ITE) initiated the National Bicycle and Pedestrian Documentation Program (NBPD) as an effort to promote greater data collection for non-motorized transportation modes, establish a consistent model for data collection, and address the lack of data access and shared research.
In 2013, the US Department of Transportation,
Federal Highway Administration
The Federal Highway Administration (FHWA) 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 a ...
(FHWA) expanded and created a chapter on non-motorized counting for the Traffic Monitoring Guide (TMG) designed to guide planning agencies in the collection of their data.
See also
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People counter A people counter is an electronic device that is used to measure the number of people traversing a certain passage or entrance. Examples include simple manual clickers, smart-flooring technologies, infrared beams, thermal imaging systems, WiFi track ...
*
Passenger Car Unit
Passenger car equivalent (PCE) or passenger car unit (PCU) is a metric used in transportation engineering, to assess traffic-flow rate on a highway.
A passenger car equivalent is essentially the impact that a mode of transport has on traffic var ...
References
{{DEFAULTSORT:Traffic Count
Road traffic management
Transportation planning
Road transport
Counting instruments