History
The first nation-wide road traffic censuses in Switzerland were held in 1928/29, 1936/37 and 1948/49. Since 1955, these counts by category and origin have been carried out every five years in line with the recommendation of the UN European Domestic Transport Committee.
Current practice
Today, traffic censuses are carried out in around thirty countries on the basis of uniform guidelines and criteria, and this makes it possible to compare traffic volumes, the proportion of heavy goods traffic and overall trends throughout Europe. And by combining various data relating to infrastructures, we are able to gain an overview of the traffic volumes on individual European trunk roads.
Implementation
In Switzerland, traffic counts in line with UN guidelines are carried out by the Swiss Road Traffic Census. The Swiss Federal Roads Authority is responsible for traffic counts in collaboration with cantonal civil engineering authorities, while the comprehensive statistical material is collected electronically by the Federal Office of Information Technology and Communications.
Methodology
The network for the 2005 Swiss Road Traffic Census encompasses 453 counting stations. Electronic counting devices from the Automatic Traffic Census network are to be used at 175 of these stations, and these are now programmed to allocate each vehicle to the corresponding category. At 134 other locations, the personnel carrying out manual counts will be supported by electronic devices for recording passenger cars. And at the remaining 144 counting stations, which are primarily located on main and secondary roads with lower traffic volumes, all vehicles are to be counted manually. Thus in comparison with earlier censuses, it will be possible to record approximately 80% of road traffic automatically and reduce the number of personnel required on the various counting days from approximately 2,000 to around 600.
The automatic counting devices are to be in operation throughout the year, while manual counts will be based on a sampling concept. Counts are to be carried out simultaneously at all manual stations during 6-hour periods on 3 working days and 4-hour periods on 2 Sundays. These days will be distributed throughout the year, commencing from 14 March 2005. The results will then be projected on the basis of daily and annual readings obtained from the associated automatic counting devices.
From now on, data concerning foreign vehicles are to be recorded separately: in order to calculate their proportion of overall road traffic, counts of foreign vehicles will be carried out manually at 27 automatic counting stations.
Results of the 2005 Swiss road traffic census
This publication contains information concerning the 2005 Swiss road traffic census. It describes the procedure and gives an overall view of all the 453 counting stations and their most important features. The maps show the location of the counting stations and the traffic density of the road network. The CD-ROM contains detailed data of all counting stations and a database with all available hourly values.