Overview
The winter road clearance services are an essential task to ensure road safety and the efficiency of the public road network. Without this service the number of accidents would increase sharply during critical winter days and road traffic would grind to a halt. The maintenance of an efficient and safe road network even in winter weather conditions is a fundamental prerequisite for the functioning of the economy and the community.
But the road winter service not only brings benefits, it also causes cost. In addition to the financial burden of the public sector arise also environmental costs. Here hung those costs among others of the applied cavities and spreading technology and the time of use from.
To date quantifying the economic advantages and disadvantages of road winter maintenance has never been tried in Switzerland.
The research study involved a quantification of the economic advantages and disadvantages of winter road maintenance. It was the first time such the quantification has been carried out in Switzerland. Where it was possible to do, the study also included a quantitative assessment of the changes in environmental costs which result from the use of winter road maintenance. The study also looked into driver behaviour on slippery road surfaces in winter.
Basis of the methodology is the combination of detailed accident data, weather records (driving-surface conditions, type of smoothness, type and intensity of precipitation, etc.), use reports of road-winter maintenance and traffic data (traffic counts and speed measurements).
The automatic traffic surveys (Vehicle, traffic volumes, velocities) occur in winter to winter and not wintry days, the latter are primarily used for comparing the driving behavior before and after the winter service. These data are complemented by simultaneous measurements in place by the specially trained test personnel, as well as through the use of reports of winter service, by the data of the ice plant, of SWIS data and accident data of the police stations.
The driving behavior is then subjected to a risk analysis. Finally, the number of accidents before and comprehensively analysed after the use of winter service.
Funding
Results
The investigation was essentially based on the method developed by the German authors Durth, Hanke and Levin (1989). The main feature of this method involves the investigation of driver behaviour in traffic on winter days at various locations, both before and after the application of winter maintenance. Details of traffic behaviour were recorded partly by specially trained observers and partly by automatic counters. The observers had to observe and record details of traffic behaviour, the weather, and the condition of the road both before and after the application of winter maintenance. The automatic counters recorded traffic volumes and vehicle speeds.
The investigation and quantification of other cost/benefit elements were made using data from additional sources these included winter maintenance records, information on costs for the maintenance depots concerned, and accident records for the relevant road sections.
The following observation points and survey stations were selected for the investigation:
- A3 near Gattikon (between Wadenswil/Thalwil, in the direction towards Zurich, average daily traffic in both directions is about 50'000)
- Al near Hunzenschwil (towards Bern,
- Average daily traffic in both directions is about 57'000)
- Al near Mattstetten (towards Bern,
- Average daily traffic in both directions is about 72'000)
- A2, near Muttenz, (towards Lucerne,
- Average daily traffic in both directions is about 116'000)
- Zurich, Rosengartenstrasse (towards the HardbrQcke, average daily traffic in both directions is about 66'000)
- St. Gallen, Rorschacherstrasse (direction away from the town, average daily traffic in both directions is about 8'000)
The first four survey stations are on motorways, the last two In the cities of Zurich and St. Gallen.
The observations and automatic counts had to be carried out during two winter periods, 2002/2003 and 2003/2004, in order to collect sufficient data for the analysis to be made. There were so few occurrences of winter road conditions at the count station near Muttenz that the investigation had to be restricted to the five other locations.
Other results
The results of the study can be used as an important argument against any budget cut plans. You can also help even justify the use of additional resources for accelerated winter maintenance.
The plan is published in the VSS magazine "Road and Traffic".