Salting for skid control of cycleways: a study of salt spread pattern and potential salt-related environmental effects

Increased travel by bicycle is an important step in order to reach a more sustainable transport system. Cycling is significantly more energy efficient per passenger kilometer compared to travelling by car, contributes to a more efficient use of land and decreases congestion in cities. At the same time it also generates positive effects on public health and decrease particles and noise. The greatest potential to increase the share of journeys by bicycle is in urban areas. If short journeys by car were replaced with walking or cycling great environmental benefits would be generated. Replacing the car with bicycling during winter generates additional environmental benefits compared to other seasons, since starting the car in cold weather generates higher emissions. Today the number of cyclists decreases during winter and in order to achieve a more sustainable transport system all year round it is thus important to increase winter cycling. One method for winter maintenance of cycleways is to use a machine with a rotating power broom, usually front-mounted, for clearing the snow and then spread saline solution (brine) or pre-wetted salt for skid control. This method has increased in popularity the most recent years as an effort to increase winter cycling and is in this thesis called "sweepsalting". When using the sweepsalt method the aim is to increase accessibility of cycleways and to increase safety for cyclists. At the same time less grit is accumulated and this can decrease the risk for accidents after winter season due to remaining grit and decrease the formation of PMio particles. On the other hand sweepsalting leads to that more salt is spread and it is well known since far back that salt has negative environmental effects. The aim of this thesis is to investigate how salt is spread to the environment of the cycleway when using the sweepsalting method and in what quantities. The aim is also to review potential environmental effects of the salt used in the method. Environmental impacts from production of the machine or its fuel consumption are not addressed in this project, only the impact from the salt used. Methods used to reach the aim were field measurements, laboratory analyses, validation of salt amount, literature review and follow-up on data. The field study was mainly conducted in Linköping on two different locations in order to compare two different sweepsalting methods. Comparative field studies were also done in Stockholm, as well as Horsens in Denmark. The field measurements of how salt is spread to the environment of the cycleway concluded that generally salt is only spread to the sides if the broom of the sweepsalter is used. Comparative measurements of salt spread pattern on a road for cars concluded that salt can be transported a much longer distance from a road, but in a higher concentration at cycleways when sweepsalting and using the broom. Positive environmental effects of the sweepsalting method are that it can lead to increased winter cycling and that gritting can be avoided, which generates better air quality. Negative environmental impacts are mainly that it contributes to increased concentrations of road salt in water and soil and that it can damage vegetation adjacent to the cycleway. To minimize these negative impacts it is important to optimize the salt amount and only use the broom during or after precipitation or when it is necessary due to grit, twigs, leaves or other unwanted items on the cycleway.

  • Corporate Authors:

    Linköping university. Department of Management and Engineering

    Linköping,   Sweden 
  • Authors:
    • Jansson, Josephine
    • Kok, Sofie
  • Publication Date: 2015

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01664415
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • Files: ITRD, VTI
  • Created Date: Mar 28 2018 10:22AM