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

  • May 25, 2023
    Transport is evolving – and road safety must keep pace, says Parifex
    France-headquartered Parifex works at the cutting edge of Lidar-based speed control systems. CEO Paul-Henri Renard discusses safety advances made in recent decades - and the causes of accidents that remain…
  • January 31, 2012
    Managing congestion, better information changes perceptions
    Kapsch's Dietrich Leihs talks about the true fundamentals of urban pricing. In some Italian and German towns and cities, the solution to congestion is an outright ban on certain types of vehicles. As far as Dietrich Leihs is concerned, any attempt to sweeten the pill that is congestion charging is only ever going to be a partial success at best.
  • March 17, 2014
    Police to enforce car ban as Paris battles smog
    Thousands of cars will be banned from Parisian roads today as the city tries to curb dangerous pollution levels by introducing alternate driving days for the first time in nearly two decades. The radical move will see around 700 police officers deployed to man 60 checkpoints around the French capital to ensure that only cars with number plates ending in odd numbers are on the streets. Parking will be free for vehicles with even number plates, the Paris city hall said, calling on residents to consult
  • December 4, 2018
    Tecsidel’s Pan-American Highway tunnel eases Lima’s traffic woes
    The Pan-American Highway connects the US and Canada with Latin America, running for thousands of miles from Alaska in the north to Argentina in the south. Mauro Nogarin finds that one tunnel built underneath it is now providing relief for thousands of travellers each day On the Pan-American Highway, the lengthy series of roads which spans both American continents - from the US state of Alaska to the Latin American country of Argentina - ITS solutions are many and varied. One of these, in Peru’s capital