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Östermalm, Sweden

Mucka P.,Slovak Academy of Sciences | Granlund J.,Vectura Consulting AB
Journal of Transportation Engineering | Year: 2012

This study quantifies and explains the paradox of a slow increase in road quality over time with a concomitant decrease in ride comfort or objective road quality. The study estimates the effect of road profile wavelength contents on the International Roughness Index (IRI) and planar personal half-car model vertical vibration response. Two cases are examined: (a) decrease in short-wave amplitudes (<2 m) and (b) increase in long-wave amplitudes (>20 m). The wavelength-content change was modulated by a change in the road profile spectrum slope (i.e., waviness) in both analyzed wavebands. The results indicate a relative insensitivity of the IRI algorithm to a change in road quality in both cases, while the particular vibration responses (dynamic tire force, seat or car body vertical acceleration) are markedly changed. It is shown that the IRI algorithm calculated for the alternative velocities should be a more robust tool to detect the change in wavelength contents in the examined wavebands. © 2012 American Society of Civil Engineers.

Mucka P.,Slovak Academy of Sciences | Granlund J.,Vectura Consulting AB
Journal of Transportation Engineering | Year: 2012

Remixing of the wearing course in the high-speed lane of a freeway resulted in a new road surface that, compared with the old surface in the adjacent low-speed lane, was perceived as a bumpy ride by road users, as well as by the road agency and the paving contractor. In this paper, the unevenness of the longitudinal road profiles of the old and the new (remixed) surfaces are analyzed and compared. The comprehensive analysis was conducted with statistical and signal processing tools. The probability density function (PDF), power spectral density (PSD), autocorrelation function, coherence, and occurrence of local obstacles in both lanes were evaluated and mutually compared. The profiles were quantified with commonly used indicators of road unevenness. The paper documents some disadvantages of the International Roughness Index (IRI) and advantages of road elevation power spectral density to reflect the ride quality of road profiles. © 2012 American Society of Civil Engineers.

Alakangas L.,Lulea University of Technology | Andersson E.,Vectura Consulting AB | Mueller S.,Boliden Mineral AB
Environmental Science and Pollution Research | Year: 2013

Backfilling of open pit with sulfidic waste rock followed by inundation is a common method for reducing sulfide oxidation after mine closure. This approach can be complemented by mixing the waste rock with alkaline materials from pulp and steel mills to increase the system's neutralization potential. Leachates from 1 m3 tanks containing sulfide-rich (ca.30 wt %) waste rock formed under dry and water saturated conditions under laboratory conditions were characterized and compared to those formed from mixtures. The waste rock leachate produced an acidic leachate (pH < 2) with high concentrations of As (65 mg/L), Cu (6 mg/L), and Zn (150 mg/L) after 258 days. The leachate from water-saturated waste rock had lower concentrations of As and Cu (<2 μg/L), Pb and Zn (20 μg/L and 5 mg/L), respectively, and its pH was around 6. Crushed (<6 mm) waste rock mixed with different fractions (1-5 wt %) of green liquid dregs, fly ash, mesa lime, and argon oxygen decarburization (AOD) slag was leached on a small scale for 65 day, and showed near-neutral pH values, except for mixtures of waste rock with AOD slag and fly ash (5 % w/w) which were more basic (pH > 9). The decrease of elemental concentration in the leachate was most pronounced for Pb and Zn, while Al and S were relatively high. Overall, the results obtained were promising and suggest that alkaline by-products could be useful additives for minimizing ARD formation. © 2013 Springer-Verlag Berlin Heidelberg.

Lindfeldt O.,Vectura Consulting AB
WIT Transactions on the Built Environment | Year: 2012

Extension of single-track lines into double-track will be an important part of future rail investments in Sweden. Most Swedish railway lines are single-track and the steady growth in demand for passenger and freight transportation calls for more capacity, which in turn imposes a need for more double-track sections. This paper points out three minor measures that can be taken on single-track lines before they are completely extended into double-tracks: additional crossing loops, extended crossing loops to enable parallel entrance, and partial doubletracks. A generic model for timetable analysis, TVEM (Timetable Variant Evaluation Model), is applied to evaluate the effect of the three measures through generation of 20,000-50,000 alternative timetables. The evaluation shows that none of the measures significantly affect the maximum capacity, i.e. the number of trains in the best timetable alternative. This indicates that the longest inter-loop distance, has to be substantially shortened through either an additional crossing loop or a partial double-track. A parallel entrance facility on a crossing loop does not affect the time distance between adjacent loops so much that it can be considered to increase maximum capacity. However, all three measures result in higher timetable flexibility, i.e. number of timetable variants for a given number of trains (capacity level). Partial doubletracks give much more timetable flexibility than additional crossing loops and parallel entrance facilities on crossing loops. It is reasonable that higher timetable flexibility imposes a higher practical, realizable capacity, since a line section that can be scheduled flexibly is less likely to constrain the overall capacity on the entire line. © 2012 WIT Press.

Schmocker J.-D.,Kyoto University | Pettersson P.,Vectura Consulting AB | Fujii S.,Kyoto University
International Journal of Sustainable Transportation | Year: 2012

Coercive policies, such as road pricing or environmental taxation, are policies of an authority that charges or restricts its subjects in order to protect or restore common goods. Studies have shown it is important to understand the acceptability of such policies to the general public to guarantee long-term success. Our analysis, based on a limited survey of British and Japanese students, investigates well-established psychological factors that determine acceptability of road pricing directly or indirectly, such as perceived effectiveness, fairness, or problem awareness, as well as the role of a general trust in the government and a belief in "absolute values." © Taylor & Francis Group, LLC.

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