Tuesday, February 1, 2011

Clean Streets and Intact Road Surfaces Help to Keep the Air Clean

It is well known that cars are a main cause of atmospheric pollution. However, the emissions coming from your tailpipe aren’t always the biggest contributor. When the weather situation favors the creation of winter smog, tailpipe emissions account for less than half of the fine particulate pollution from your car. The majority of this pollutant is produced by mechanical wear and resuspension of dust due to air turbulence from passing vehicles.
The fine particle matter released by combustion processes, and mechanical wear, and that thrown up again swirling air can no longer move into the higher layers of the atmosphere, with the result that the concentration at ground level increases. Working together with the Road Engineering / Sealing Components Laboratory, the atmospheric specialists developed a new measuring method using Empa's Traffic Load Simulator. This machine is normally used to investigate the time-accelerated resistance to wear of road surfaces under extreme load conditions.
The results of the study showed that in urban area debris from vehicle brakes contributes about 20% of the fine particle emissions from road traffic because of the regular nature of traffic flow. Damaged roads surfaces, on the other hand, can result in quite high fine particle emission levels. What this means is that keeping roads as clean as possible and in good repair makes a significant contribution to reducing the problem of fine particulate emissions.

Empa. "Clean streets and intact road surfaces help to keep the air clean." ScienceDaily 1 February 2011. 1 February 2011 .


  1. I never thought that it was even possible for another air pollutant caused by cars to be similarly as bad as carbon emissions. This is a great example of how much there is to learn about the complex problems humans are causing for the earth. I think its great that there is an effort of reducing this particulate air pollution, but will the further repairs to the roads cause more damage than help? Won't the repairs be done by large machinery and trucks that produce large amounts of carbon emissions?

  2. I recall reading previously about particulates from car brakes. This may be something that reformulation can help, though it will require engineering to get the right balance of reducing particulates while keeping costs and other environmental factors in mind during in the manufacturing process.

    I agree with Karie that keeping the roads in repair has other costs and pollution associated with the heavy equipment, so the air quality issue is complex. Another consideration may be road design. I also recall reading that roads in some other countries are designed with a longer lifetime duration, which could potentially reduce potholes and dust and damage associated with them. Often the lower short term costs are favored over higher upfront costs for the longterm solution, but the longterm solutions often offer savings in the end. Highway 30 near me was made thicker than normal for the longterm benefit, and after ten years it still looks relatively new, and repairs seem to have been minimal.