| 11. |
- Shinar, David, et al.
(författare)
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Reporting bicycle accidents to police in the COST TU1101 survey data base: Cross-country comparisons and associated factors
- 2016
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Ingår i: ; , s. 9-9
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Konferensbidrag (refereegranskat)abstract
- Police crash reports are often the main source for official data in many countries. However, police sampling and data are known to be subject to bias, making the countermeasures adopted according to them possibly inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling. The following paper utilizes data collected in the COST TU1101 action. The data came from an online survey that included questions related with bicyclists' attitudes, accidents, and pattern of use of helmets. An average of only 10% of all crashes were reported to the police (minimum of 0.0% Israel and 3.37% Greece to a maximum of a 30% of Germany). Some factors associated with the reporting level were: type of crash, type of vehicle and injury severity. Finally, no relation was found between the likelihood of reporting and the cyclist's gender, age, use of helmet, and type of bicycle. The significant under-reporting justifies the use of survey data for assessment of bicycling crash patterns as they relate to crash risk issues such as location, cyclists' characteristics, and use of helmet and strategic approaches to bicycle crash prevention and injury reduction, which are discussed in the paper.
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| 12. |
- Shinar, David, et al.
(författare)
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Under-reporting bicycle accidents to police in the COST TU1101 international survey: Cross-country comparisons and associated factors
- 2018
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Ingår i: Accident Analysis and Prevention. - : Elsevier BV. - 0001-4575. ; 110, s. 177-186
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Tidskriftsartikel (refereegranskat)abstract
- Police crash reports are often the main source for official data in many countries. However, with the exception of fatal crashes, crashes are often underreported in a biased manner. Consequently, the countermeasures adopted according to them may be inefficient. In the case of bicycle crashes, this bias is most acute and it probably varies across countries, with some of them being more prone to reporting accidents to police than others. Assessing if this bias occurs and the size of it can be of great importance for evaluating the risks associated with bicycling.This study utilized data collected in the COST TU1101 action “Towards safer bicycling through optimization of bicycle helmets and usage”. The data came from an online survey that included questions related to bicyclists' attitudes, behaviour, cycling habits, accidents, and patterns of use of helmets. The survey was filled by 8655 bicyclists from 30 different countries. After applying various exclusion factors, 7015 questionnaires filled by adult cyclists from 17 countries, each with at least 100 valid responses, remained in our sample.The results showed that across all countries, an average of only 10% of all crashes were reported to the police, with a wide range among countries: from a minimum of 0.0% (Israel) and 2.6% (Croatia) to a maximum of a 35.0% (Germany). Some factors associated with the reporting levels were type of crash, type of vehicle involved, and injury severity. No relation was found between the likelihood of reporting and the cyclist's gender, age, educational level, marital status, being a parent, use of helmet, and type of bicycle.The significant under-reporting – including injury crashes that do not lead to hospitalization – justifies the use of self-report survey data for assessment of bicycling crash patterns as they relate to (1) crash risk issues such as location, infrastructure, cyclists' characteristics, and use of helmet and (2) strategic approaches to bicycle crash prevention and injury reduction.
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| 13. |
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| 14. |
- Tröstl, Jasmin, et al.
(författare)
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The role of low-volatility organic compounds in initial particle growth in the atmosphere
- 2016
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 533:7604, s. 527-531
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Tidskriftsartikel (refereegranskat)abstract
- About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst of new particles near midday(1). Atmospheric observations show that the growth rate of new particles often accelerates when the diameter of the particles is between one and ten nanometres(2,3). In this critical size range, new particles are most likely to be lost by coagulation with pre-existing particles(4), thereby failing to form new cloud condensation nuclei that are typically 50 to 100 nanometres across. Sulfuric acid vapour is often involved in nucleation but is too scarce to explain most subsequent growth(5,6), leaving organic vapours as the most plausible alternative, at least in the planetary boundary layer(7-10). Although recent studies(11-13) predict that low-volatility organic vapours contribute during initial growth, direct evidence has been lacking. The accelerating growth may result from increased photolytic production of condensable organic species in the afternoon(2), and the presence of a possible Kelvin (curvature) effect, which inhibits organic vapour condensation on the smallest particles (the nano-Kohler theory)(2,14), has so far remained ambiguous. Here we present experiments performed in a large chamber under atmospheric conditions that investigate the role of organic vapours in the initial growth of nucleated organic particles in the absence of inorganic acids and bases such as sulfuric acid or ammonia and amines, respectively. Using data from the same set of experiments, it has been shown(15) that organic vapours alone can drive nucleation. We focus on the growth of nucleated particles and find that the organic vapours that drive initial growth have extremely low volatilities (saturation concentration less than 10(-4.5) micrograms per cubic metre). As the particles increase in size and the Kelvin barrier falls, subsequent growth is primarily due to more abundant organic vapours of slightly higher volatility (saturation concentrations of 10(-4.5) to 10(-0.5) micrograms per cubic metre). We present a particle growth model that quantitatively reproduces our measurements. Furthermore, we implement a parameterization of the first steps of growth in a global aerosol model and find that concentrations of atmospheric cloud concentration nuclei can change substantially in response, that is, by up to 50 per cent in comparison with previously assumed growth rate parameterizations.
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