Traffic Surveys

Traffic Surveys


Traffic survey definition means to capture data that accurately reflects the real-world traffic situation in the area. It may be counting the number of vehicles using a road or collecting journey time information for example, but there are many other types of data that traffic surveys collect.

Importance of traffic surveys arises when it comes to transport planning, an essential basic requirement is obtaining a sound understanding of the actual conditions on the ground in order to predict what the conditions would be in the future. Often, the only way to achieve this is by obtaining an accurate measure of traffic (vehicle/pedestrian) numbers. This is often expanded to encapsulate vehicle types and speeds. If the objective requires more detailed data, then the journey length, the purpose of the journey and the frequency of the journey may also need to be determined.

Purpose of traffic surveys include helping to resolve national, regional and local traffic issues. In particular, the data gathered plays a major role in informing the decision making process in transport planning. This may include contributing to projects related to the planning, construction and maintenance of transport infrastructure. Importantly, with major investment apparently in short supply, traffic survey reports influence investment in future infrastructure as well as making the best of our current road networks. On a local level surveys are also utilized for smaller projects to generate traffic volume study report and traffic impact study report that deal with parking issues or the effectiveness of traffic calming measures in regards to road safety issues.

A traffic survey type can include many kinds of traffic data collection:

  • Traffic counts survey (traffic volume counts survey)
  • Turning movement counts at intersections
  • Travel time survey
  • Trip generation data collection
  • Origin – destination data collection
  • Household survey
  • Transit oriented survey (Fare structure survey, Bus route Survey, Occupancy Survey, Transfer Survey)
  • Other social surveys

There are a variety of traffic count or traffic survey methods used on UK traffic networks ranging from manual counting, pneumatic road tubes and video cameras to emailed traffic survey questionnaire and telephone surveys.

In the past practices, traffic volume count approach involved people standing by the sideways of roads and recording their observations on paper. In current years, this method has been broadly substituted by recording traffic using video recorder, and then examining the video footage later in the office.

A list of different in-situ sensor traffic count equipment (Klein et al. 2006)

Sensor TechnologyCountSpeedVehicle classificationOccupancyPresenceMultilane
Pneumatic road tubes traffic counterYesYesYesNoNoNo
Magnetic loopYesWith dualNoYesYesNo
Inductive loopYesWith dualYesYesYesNo
Video processingYesYesYesYesYesYes
Active InfraredYesYesYesNoNoYes
Passive InfraredYesYesNoYesYesNo
Microwave RadarYesYesYesYesYesYes
Passive acousticsYesYesNoYesYesYes