There’s a fierce debate in Trondheim, NTNU’s home, as to whether the speed limit in the centre of the city should be dropped from 50 to 30 kilometres per hour. The arguments for lowering the speed limit are many – better air quality is just one of them. But until now, there hasn’t been any concrete information about the effect that lower speeds have on the amount of fine dust on the roads.
NTNU researcher Brynhild Snilsberg has examined the occurrence of fine dust in the summer and winter from winter tyres, summer tyres and studded tyres – and has measured the amount of dust associated with different speeds.
Her results show that the amount of road dust from studded tyres is halved when speeds drop from 50 to 30 km/hour. The dust particles are also less finely ground.
Fast studs, fine dust
“In general, it turns out that the amount of dust that is produced and kicked up increases proportionally with the speed, so that the amount increases from about 2.5 milligrams per cubic metre of air at speeds of 30 km/hr, to a little over 5, at 50 km/hr”, says Snilsberg.
“Also, the particles are on the whole much smaller with higher speeds. The increased speed enables the studs to grind the dust more finely”, explains Snislberg.
“That’s a strong argument for reducing the speed limit in the city, particularly in the winter months”, says the researcher.
Stronger than expected
Snilsberg says she wasn’t surprised to find the trend. “But I didn’t think it would be so strong”, she says.
Roughly three of 10 automobiles in Trondheim are outfitted with studded tyres. Consequently, a halving of the amount of fine dust caused by studded tyres will have a considerable effect on the total amount of dust in the city centre. The national average for the use of studded tyres is 45 per cent.
The problem with road dust from studded tyres is increasing, as both the amount of traffic and the demand for ice- and snow-free roads increase. That means that roads in residential areas outside of the city centre and the more built-up areas will also be affected by this nuisance.
A need for better measurements
The dust in question is called PM 10, particulate matter that is 10 micrometres or less in diameter. The current measurement requirements, which are EU certified, are based exclusively on weight. That isn’t a very adequate standard, Snilsberg believes.
“If you have one particle that’s one milligram on the one hand, and a thousand fine particles that together weigh the same on the other, there’s no doubt as to which is more harmful to your health. But we don’t have any better alternative when it comes to measuring and monitoring air quality in Norwegian cities”, she says.
Snilsberg took her PhD at the Department of Geology and Mineral Resources Engineering at NTNU, and conducted her research at the Norwegian Public Roads Administration.
By Tore Oksholen/Gemini
Nina Tveter | alfa
Study sets new distance record for medical drone transport
13.09.2017 | Johns Hopkins Medicine
Researchers 'count cars' -- literally -- to find a better way to control heavy traffic
10.08.2017 | Florida Atlantic University
On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.
We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...
What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...
For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.
Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...
At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.
No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...
Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.
Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...
08.01.2018 | Event News
11.12.2017 | Event News
08.12.2017 | Event News
19.01.2018 | Materials Sciences
19.01.2018 | Health and Medicine
19.01.2018 | Physics and Astronomy