Traffic survey

from Wikipedia, the free encyclopedia
Section from a counting sheet
Traffic count by sensors in the lane on the M8 in Ireland
Side radar at the edge of the B 106 lane

The traffic survey or traffic count is the determination of the number of vehicles that drive through a street section or an intersection in a certain period of time. It is the basis for an economical and planned improvement of transport connections .

Basics

A basic distinction is made between two types of survey. On the one hand, there is the count, which deals with the pure number of vehicles and, on the other hand, there is observation and questioning, which deals with the reason for the journey. Which of these basic types of survey is used depends on the results that are to be obtained with the survey.

In contrast to counting, observations and surveys can usually not be carried out automatically. There are already approaches to this in freight transport, where data can be transferred directly from an EDP system. Such a computer system was developed for the truck toll in Germany .

In principle, a distinction must also be made between personal (“surveys”) and spatial (“counts”) surveys. The spatial survey is further subdivided into a spatial survey in the narrower sense and a network-related survey. In the first, the movement of an object or a person in space is mapped directly (e.g. using satellite or mobile phone location), in the second, the movements of this person are mapped in a network. A particular problem is the assignment of the movements of a person or an object to the individual modes of transport, for example to determine the modal split .

Pursuant to § 36. 5 of the Road Traffic Regulations police officers must "road users traffic control including control of the ability to drive and stop at traffic surveys."

Types of elevation

Traffic count

The traffic count is divided into the following four types.

Object counting

When counting objects, people and / or vehicles are counted who are in a specific observation area within a defined period of time. When counting objects, it is usually only counted and no distinction is made between the individual objects to be counted. However, this counting variant is too imprecise and should be replaced by a higher count.

Cross-section counting

When counting cross-sections, people and / or vehicles are counted which pass a certain point on a street, the so-called cross-section, within a defined period of time. A distinction is made either between the individual means of transport or according to the type of vehicle. Combinations of both types are also possible.

Node elevation

A node survey is a more complex form of cross-section counting. In addition to the number of vehicles coming out of a branch of the intersection, there is also the direction in which they leave the intersection. In addition, the number of crossing pedestrians in the survey per direction is determined here.

If necessary, the length of the traffic jam must be determined at nodes with a traffic light system. As soon as a traffic jam occurs, a count only represents the efficiency of the intersection access points at the time of the traffic count. Traffic jams are not the vehicles that wait on "red" and pass the intersection with the next "green", but only the vehicles that cannot be processed when the signal is "green", i.e. have to wait until the next green phase.

Electricity collection

A current survey is a survey that records the traffic in a larger area ( cordon ). It consists of several cross-sectional censuses and intersection surveys. In addition to the number, the license plate number of the vehicle is also noted or the vehicle is provided with a slip of paper. This survey is intended to determine which vehicles are crossing, entering or leaving the cordon.

observation

The characteristics of a road user and their behavior in road traffic are determined by observation . This observation is often carried out using video recordings . In addition, the road users are divided into different groups.

survey

The aim of a survey is to determine past or planned traffic activities and the reasons for these activities. The road users are questioned directly. The results of all types of survey are bundled and mostly evaluated anonymously.

Survey in the transport network

During the survey in the transport network, people, for example the users of public transport , are interviewed at selected points or in the transport itself. Mainly the starting point and destination, but partly also the purpose of the journey and some socio-demographic information are determined.

Household survey

Household surveys are surveys that can be carried out either by telephone or in writing. In most cases, a standardized questionnaire is used to ask for information on various types of behavior in traffic. The households are usually determined randomly.

Survey at the place of activity

Surveys of this kind usually take place in the parking lots in the vicinity of leisure facilities. As with the household survey, questionnaires are also used here.

Survey at the workplace

These surveys are used to record commuter and freight traffic. The survey is usually done in writing. Since freight traffic, in particular, is a sometimes very complex network of links, only a partial recording of traffic behavior is usually carried out.

Structure of the survey

Several subdivisions can take place as part of a traffic survey. What is important is usually the choice of transport mode . Furthermore, a distinction is made according to the object being transported. There is a division into passenger and freight traffic.

In passenger transport, a distinction is made between individual and public transport . In addition to pedestrian traffic and bicycle traffic , private transport also includes the use of vehicles , motorcycles (also known as motorcycles), mopeds , mopeds , scooters and trucks . Public transport includes journeys by taxi , bus , trolleybus , tram , light rail , underground , S-Bahn , train , ship and plane .

In addition, it is broken down according to the purpose of the journey; a distinction is made between private journeys and journeys in the context of professional activity. This includes trips to the place of residence, to work and training, for errands and in leisure time to private trips. In contrast to the legal aspect, where journeys to and from the workplace are also considered to be work-related, only journeys to perform work are rated as business journeys.

Survey times

The day is divided into two sections as part of a traffic survey. Daytime traffic takes place between 6:00 a.m. and 10:00 p.m. and night traffic between 10:00 p.m. and 6:00 a.m. In the case of daytime traffic, morning traffic between 6:00 a.m. and 10:00 a.m. and afternoon traffic between 3:00 p.m. and 7:00 p.m. are often recorded separately. The traffic density is subject to strong fluctuations over the course of a day and depending on the study area. The following times can usually be expected to have the highest traffic volume:

area Counting time
Residential area , streets on the outskirts, roads outside the city 6: 00–9: 00 and 15: 00–19: 00
Downtown, main downtown streets 7: 00-10: 00 and 15: 00-19: 00
industrial Estate 6: 00–9: 00 and 15: 00–18: 00
Mixed area, school area 7: 00-9: 00 and 13: 00-19: 00

A representative count should be carried out in April, May, June, September or October and on a Tuesday or Thursday (so-called normal working days) in order to minimize the influence of the weekend. In addition, days immediately before and after public holidays or at the beginning and end of vacation should be avoided.

Acquisition methods

Temporary bicycle counting system

In addition to manual recording by instructed persons (with a counting device or tally sheet), there are various methods of automatically recording the volume of traffic (traffic measurement):

  • Traffic counting through induction loops permanently embedded in the road surface
  • Plate counting by counting devices temporarily installed in the middle of the roadway, which are usually protected by an inconspicuous black plastic cover. These measuring plates are used to count cross-sections and, in addition to the number of vehicles, also record their length and speed without contact via the change in the magnetic field. Some devices can also determine the temperature and humidity of the road surface.
  • Side radar devices are also used to count cross-sections. A device installed on one side of the road can record traffic in both directions at the same time on a two-lane road. However, as the volume of traffic increases, so does the counting error caused by vehicles passing the side radar device at the same time and thus only being recognized as a single vehicle.

Automatic measurements are often less accurate than manual measurements. In order to estimate the accuracy of automatic measurements, it can be useful to carry out manual comparison measurements. In Germany, traffic volume is determined or calculated on the basis of automatic and manual measurements .

See also

literature

  • Traffic Survey Recommendations - EVE . Research Society for Roads and Transportation , Cologne 2012.
  • B. Heuel-Fabianek: Traffic census 2004 in the research center Jülich. Cross-sectional census, data collection year 2004, with an example of a data entry sheet.
  • S. Meier: Road Traffic Census 2005 - Implementation and Results. In: bau intern. No. 5/6, 2007.
  • Siedlungsverband Ruhrkohlen district: overall traffic planning for the Ruhrkohlen district. Joint work: Siedlungsverband Ruhrkohlengebiet, Federal Railway Directorate Essen, Association of Local Transport Companies Ruhr-Wupper-Niederrhein e. V. (GNR). F. Krupp Grafische Anstalt, Essen 1953.
  • G. Steierwald, GHD Künne, W. Vogt: Urban traffic planning: Basics, methods, goals. Springer-Verlag, Berlin / Heidelberg 2005, ISBN 3-540-40588-7 , pp. 80-139.
  • R. Underberg: Provision and use of measured values ​​of the traffic flow in local public transport in rural areas. Dissertation. Technical University, Munich 2004.

Web links

Commons : Traffic counters  - collection of images, videos and audio files
Wiktionary: traffic census  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. Explanations for cross-section counting , measuring technique flour; accessed in February 2017
  2. Explanations for cross-section counting , measuring technique flour; accessed in February 2017
  3. see error discussion in the traffic report in the context of the project-related development plan Regenerstraße in Friedrichshafen , p. 10ff and p. 43; accessed in February 2017