Skip to main content

Reducing high levels of particles in tunnels

A new study from Sweden’s National Road and Transport Research Institute (VTI) which aims to improve understanding of the differences between inhalable particles in highway versus railway environments has indicated that older types of trains produce more particulate emissions in railroad tunnels than do newer ones. Dust binding, improved paving and reduced studded tyre use could reduce coarse particle levels in road tunnels.
March 1, 2017 Read time: 2 mins

A new study from Sweden’s National Road and Transport Research Institute (5230 VTI) which aims to improve understanding of the differences between inhalable particles in highway versus railway environments has indicated that older types of trains produce more particulate emissions in railroad tunnels than do newer ones. Dust binding, improved paving and reduced studded tyre use could reduce coarse particle levels in road tunnels.

The tests were carried out in Sweden at Arlanda Central station beneath Arlanda Airport and in the Söderleden road tunnel in central Stockholm. The results indicate that the environment of the studied railroad tunnel is characterised by peaks in coarse particle concentration. Some trains can be tied to emissions of ultrafine particles which consist mainly of iron, with lesser amounts of copper, zinc and other metals.

The main focus of measures to remedy high particle counts in railway tunnels has so far been on preventing exposure by separating trains from platforms or using ventilation to remove polluted air, but few studies have examined the means available to prevent the emissions themselves.

According to VTI researcher Mats Gustafsson, the study demonstrates that it is possible to reduce particulate emissions by identifying and improving train types as well as individual trains and their characteristics.

Road tunnels are characterised by high levels of ultrafine particles and high levels of coarse particles when conditions are dry. Because the traffic in such tunnels is more intense than in railroad tunnels, the particle levels are more consistently high during rush hours.

“The options available to combat coarse particles in road tunnels comprise reduced studded tyre use, better paving, and efficient dust binding and cleaning”, said Gustafsson.

The ultrafine particles that occur in high concentrations derive from vehicle exhaust and can be addressed by reducing traffic volumes, improving exhaust treatment, and lowering the proportion of heavy traffic, he says.

Related Content

  • January 24, 2012
    Improve and increase mass transit systems to minimise congestion
    Rather looking to solve congestion by spreading the load, perhaps we need to look at concentrating it. Michael L. Sena writes. We humans were made to walk and run at embarrassingly slow speeds by comparison with other, more fleet-footed organisms. The sea is not our natural habitat and we were definitely not designed to fly unaided. Nevertheless, humankind has evolved a method of living during the past century that is dependent on transporting its members over very long distances during relatively short per
  • August 30, 2013
    Funding boost to cut pollution from local buses
    Towns and cities in England are set to benefit from US$7.7 million of funding to reduce pollution from local buses, Local Transport Minister Norman Baker has announced. A total of eleven local authorities have been awarded grants from the Department for Transport’s (DfT) Clean Bus Technology Fund, which will allow almost 400 buses to be upgraded.
  • March 16, 2015
    Report analyses multiple ITS projects to highlight cost and benefits
    Every year in America cost benefit analysis is carried out on dozens of ITS installations and pilot studies and the findings, along with the lessons learned, are entered into the Department of Transportation’s (USDOT’s) web-based ITS Knowledge Resources database. This database holds more than 1,600 reports and periodically the USDOT reviews the material on file to draw conclusions from this wider body of evidence. It has just published one such review ITS Benefits, Costs, and Lessons Learned: 2014 Update Re
  • September 11, 2023
    Reducing climate impacts starts at the intersection, says Inrix
    The tools to identify and reduce unnecessary delays at intersections are here – and traffic signal performance improvement is also eligible for US government funding, points out Rick Schuman of Inrix