Traffic count

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"Traffic counter" redirects here. For traffic counting in computer networks, see Network traffic measurement.
Bike counter with display showing the number of bikes on the particular day and accumulative for the year, for one bike lane in Copenhagen.

A traffic count is a count of traffic along a particular road, either done electronically or by people counting by the side of the road.[1] 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. They are useful for comparing two or more roads, and can also be used alongside other methods to find out where the CBD of a settlement is located. Traffic counts that include speeds are used in speed limit enforcement efforts, highlighting peak speeding periods to optimise speed camera use and educational efforts.

Counting methods[edit]

A traffic counter on BIA road J-9 in the United States
Pneumatic road tube counter with the tube on the roadway and the counting device on the sidewalk

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 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 count table[edit]

This is a traffic count table, showing the type of vehicle and the data collected at mock site. This data has been compiled into numbers from each direction and a total count.

Vehicle Type Lane 1 Lane 2 Total
Bicycles 5 2 7
Passenger Cars 48 47 95
Passenger Trucks 15 9 24
Buses 3 2 5
Semi-Truck/Lorry 16 11 27

Traffic counter devices[edit]

Traffic counter system using inductive loops connected to a cabinet with solar panels and 3g modem to transmit traffic information.
A radar-based traffic counter (about 2/3 of the way up the pole) powered by a solar panel (near top of pole).

A traffic counter is a device, often electronic in nature, used to count, classify, and/or measure the speed of vehicular 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 road tubes laid across the roadway, piezo-electric sensors embedded in the roadway, inductive loops cut into the roadway, or a combination of these to detect the passing vehicles. Pneumatic road tubes are generally used for temporary studies to study a sample of traffic, while piezo-electric 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.[2] Recently, off-road technologies have been developed. These devices generally use some sort of transmitted energy such as radar waves or infrared 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.[3][4]

Bicycle traffic counting devices[edit]

Technologies for counting bikes on roads and bike paths have progressed with the increased emphasis on the economic, environmental and social benefits of multi-modal traffic networks. Bikes can be surveyed using the same sensors, tuned to be more sensitive.


  1. ^ "FHWA Traffic Monitoring Guide". June 2013. Retrieved March 2015
  2. ^ "Strip Across Road Counts Cars and Registers Hourly Total" Popular Mechanics, July 1936
  3. ^ Evaluation of Microwave Radar Trailers for Nonintrusive Traffic Measurements." Transportation Research Record: Journal of the Transportation Research Board 1917 (2005): 127-40. Transportation Research Record: Journal of the Transportation Research Board Online.
  4. ^ Middleton, D.R., R.T. Parker, and R.R. Longmire. "Investigation of Vehicle Detector Performance and ATMS Interface.", Texas Transportation Institute 0-4750-2 (2007). Texas Transportation Institute.