| 1. |
- Aakjer Nielsen, Michael
(författare)
-
Accidents on rural roads in Denmark
- 2000
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Ingår i: Proceedings of Traffic Safety on Two Continents. Conference in Malmö, Sweden, September 20-22, 1999. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 1-16
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Aakjer Nielsen, Michael, et al.
(författare)
-
Signing and marking of substandard horizontal curves on rural roads
- 1998
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Ingår i: Proceedings of Road safety in Europe. Conference in Bergisch Gladbach, Germany, September 21-23, 1998. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 25-38
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Abadir Guirgis, Georg
(författare)
-
Ecodriving på SJ : förarperspektiv på tekniska hjälpmedel för beslutsfattande och utbildning i Ecodriving
- 2013
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Trots att samtliga resor med SJs tåg i Sverige är märkta med Bra Miljöval skärps kraven på minskade utsläpp och energianvändning efter hand, varför SJ ständigt måste utveckla sin miljöprofil. På SJ har man därför arbetat fram en utbildning i energieffektiv körning (Ecodriving) samt låtit vissa av sina förare använda ett tekniskt hjälpmedel som stödjer detta, för att påvisa möjligheten till energibesparingar. Denna rapport tar upp två studier vilka är SJs försöksverksamhet inklusive en kritisk granskning av denna samt en kompletterande studie i form av observationer av utbildning i Ecodriving och intervjuer med förare. Resultaten av SJs försöksverksamhet är värdefulla och talar för att energibesparingar är genomförbara. Samtidigt så finns det en hel del osäkerhet i de energimätningsdata som samlats in varför det är svårt att dra några definitiva slutsatser. Resultatet av intervjuerna med förarna talar för att det finns en hel del oklarheter kring vilka risker och konsekvenser ett framtida införande av det tekniska hjälpmedlet för Ecodriving faktiskt innebär. Sammantaget finns anledning att genomföra fortsatta studier av hur man på bästa sätt kan införa energieffektiv körning av spårtrafik i sin helhet.
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| 4. |
- Abadir Guirgis, Georg, 1988-, et al.
(författare)
-
Lokförarutbildning i Sverige : simulatoranvändning och ERTMS
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta notat ger en översiktlig bild av den obligatoriska grundutbildningen till lokförare i Sverige och belyser i vilken mån simulatorbaserad träning förekommer inom utbildningen. Rapporten visar vilka möjligheter och begränsningar som finns med att öka användningen av simulatorer i lokförarutbildningen, samt beskriver de viktigaste styrdokumenten för lokföraryrket och lokförarutbildningen. Vidare presenteras Transportstyrelsens utbildningsplan för förarbevis och de aktörer som bedriver grundutbildning, fortbildning och examination. Trafikverkets E-Learning för ERTMS, ERSA-simulatorn samt operatörsspecifika ERTMS-utbildningar vid SJ och Green Cargo beskrivs. Forskarna har dessutom undersökt svenska tågoperatörers och utbildares nuvarande användning och framtida behov av simulatorer för grund- och fortbildning av lokförare. Exempel från andra domäner där simulatorer används i utbildningssammanhang lyfts också fram i rapporten.
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| 5. |
- Abadir Guirgis, Georg
(författare)
-
Lärarperspektiv på riskutbildningen för motorcyklister
- 2011
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Over the last decade it has become increasingly popular to ride a motorcycle in Sweden. A mandatory risk education for competence A and A1 was introduced from the 1st of November 2009. Since the education is new, few evaluations have been conducted so far.This study evaluates the risk education for motorcyclists based on the perspective of driving instructors. The goal was to compile the instructors' comments and experiences with respect to the new risk training. An additional objective was to examine the driving instructors' perceived effects of the education on their students' driving behavior. Six semi-structured interviews with driving instructors and an observational study of the education at various driving schools were conducted. In addition, a participant observation study was performed during a further education of 15 driving instructors. The results show that the instructors experience a great need for the new risk training and that the implementation of the training itself has been good. Students have been referring to the risk training, which according to the instructors indicate that the students have embraced the essence of the training. As a result, the students drive more carefully now and think twice in certain situations according to the instructors. This was considered a desirable result.
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| 6. |
- Abadir Guirgis, Georg, 1988-, et al.
(författare)
-
Simulatorbaserad utbildning i ERTMS : utvärdering av utbildning och träning för lokförare i VTI:s tågsimulator
- 2015
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta notat presenterar en studie för att utvärdera VTI:s tågsimulator för träning och utbildning i ERTMS (European Rail Traffic Management System) för lokförare. Resultaten visar att både lärare och elever är mycket positiva till den simulatorbaserade träningen och mycket tyder på att teori och simulatorträning som varvas ger bäst resultat. På sikt ska de större järnvägsstråken i Sverige utrustas med ERTMS. Detta kommer kräva stora utbildningsinsatser för Sveriges cirka 3 500 lokförare. Det är orealistiskt att dessa ska utbildas på riktiga spår och det finns ett behov av en mer realistisk ERTMS-simulator än den ERSA-simulator som Trafikverket erbjuder idag. Studiens syfte var därför att utvärdera VTI:s tågsimulator, dels jämfört med European Rail Software Applications (ERSA) simulatorn, dels för att studera två olika sätt att kombinera teoretisk utbildning med praktisk träning i simulator. Tre olika grupper jämfördes: Teoretisk utbildning i ERTMS kombinerat med träning i ERSA-simulator (grupp 0), teoretisk utbildning i ERTMS som avslutades med träning i VTI-simulatorn (grupp 1) och teoretisk utbildning i ERTMS som till viss del varvades med träning i VTI-simulatorn (grupp 2). Grupp 1 och 2 fick avsluta utbildningen med ett teoretiskt prov och ett praktiskt körprov i simulator. Grupp 0 endast fick göra det teoretiska provet.
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| 7. |
- Abate, Megersa, 1980-, et al.
(författare)
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A disaggregate stochastic freight transport model for Sweden
- 2019
-
Ingår i: Transportation. - : Springer. - 0049-4488 .- 1572-9435. ; 46:3, s. 671-696
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents estimation results for models of transport chain and shipment size choice, as well as an implementation of the estimated disaggregate models (for two commodity groups), in the context of the national freight transport model for Sweden. The new model is a disaggregate and stochastic (logit) model, whereas the existing Swedish national model is deterministic. One advantage of the new approach is that it bases the underlying behavior of shippers on a stronger empirical foundation (that is micro-data from the Swedish Commodity Flow Survey, CFS). Another advantage is that it overcomes a well-known disadvantage of deterministic models that lead to implausibly large responses to changes in scenario or policy variables. Although estimation and implementation of aggregate stochastic models were done before, in the context of a national freight transport forecasting model, we think this is the first implementation of disaggregate freight transport chain and shipment size models estimated on choice data for individual shipments, certainly in Europe. We carried out a number of model runs with both versions of the implemented model to compare elasticities and found that transport cost and time elasticities for tonne-km are smaller (in absolute values) in the disaggregate stochastic model than in their deterministic counterparts.
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| 8. |
- Abate, Megersa
(författare)
-
Determinants of Capacity Utilisation in Road Freight Transportation
- 2014
-
Ingår i: Journal of Transport Economics and Policy. - 0022-5258 .- 1754-5951. ; 48, s. 137-152
-
Tidskriftsartikel (refereegranskat)abstract
- Recent performance indicators in the European road freight transport sector show there is an excess capacity. To shed light on this, this paper studies two aspects of capacity utilisation in trucking: the extent of empty running and the load factor. Using a joint econometric modelling framework, the paper shows that they can be explained as a function of haul, carrier, and truck characteristics. For estimation, a unique dataset from the Danish heavy vehicle trip diary was used. The results indicate distance and being a for-hire carrier have a positive effect on capacity utilisation, whereas the effect of truck size is non-linear.
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| 9. |
- Abate, Megersa, 1980-
(författare)
-
Does fuel price affect trucking industry’s network characteristics? : evidence from Denmark
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The 2000s were dominated by rising fuel prices and economic recession. Both had an impact on the structure of the trucking industry and how freight was moved. This paper examines how fuel prices shaped trucking industry’s network characteristics such as the average length of haul, average load, and capacity utilization. In particular, we show the effect of fuel price on average length of haul using 29 quarterly independent surveys from the Danish heavy goods vehicle (HGV) trip diary from 2004 to 2011. The results show that the average length of haul is sensitive to changes in fuel price: a DKK 1 (0.18$) increase in diesel price/liter leads to a 4 percent decrease in the average length of haul in the 2004-2007 period. This implies that firms improve transport efficiency by reducing the number of kilometers needed to transport a tonne of cargo as a short run response to fuel price increases. This result, however, is not confirmed for the years following the 2008 financial crisis. It also depends on where in the distribution of the average length of haul one looks.
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| 10. |
- Abate, Megersa
(författare)
-
Economic effects of air transport market liberalization in Africa
- 2016
-
Ingår i: Transportation Research Part A. - : Elsevier. - 0965-8564 .- 1879-2375. ; 92, s. 326-337
-
Tidskriftsartikel (refereegranskat)abstract
- Although the aviation industry is increasingly becoming important for Africa's economic development and integration, the ability of airlines to access foreign markets remains hindered by restrictive regulatory policies. Attempts have been made to fully liberalize the intra-African air transport market. Except for general assertions about the merits/demerits of liberalization, our empirical understanding of the welfare effects of such polices in Africa remains rudimentary. This study empirically measures the economic effects of air transport liberalization, mainly on two supply side variables: fare and service quality, measured as departure frequency. The empirical models evaluate how air fares and departure frequency respond to measures of openness in air services agreements, while controlling for other determinants. The results show up to 40% increase in departure frequency in routes that experienced some type of liberalization compared to those governed by restrictive bilateral air service agreements. Furthermore, there is a relatively larger increase in departure frequency in routes which experienced partial liberalization compared to fully liberalized ones. This can be explained by the diminishing marginal effect of progressive liberalization on departure frequency. While the effect of liberalization is substantial in improving service quality, there is no evidence of its fare reducing effect.
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| 11. |
- Abate, Megersa, 1980-
(författare)
-
Economic effects of air transport market liberalization in Africa
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Although the aviation industry is increasingly becoming important for Africa's economic development and integration, the ability of airlines to access foreign markets remains hindered by restrictive regulatory policies. Attempts have been made to fully liberalize the intra-African air transport market. Except for general assertions about the merits/demerits of liberalization, our empirical understanding of the welfare effects of such polices in Africa remains rudimentary. This study empirically measures the economic effects of air transport liberalization, mainly on two supply side variables: fare and service quality, measured as departure frequency. The results show up to 40 % increase in departure frequency in routes that experienced some type of liberalization compared to those governed by restrictive bilateral air service agreements. While the effect of liberalization is substantial in improving service quality, there is no evidence of its fare reducing effect.
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| 12. |
- Abate, Megersa, 1980-, et al.
(författare)
-
Joint econometric models of freight transport chain and shipment size choice
- 2014
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In freight transportation, decisions regarding the choice of transport mode (or chains of modes) and shipment size are closely linked. Building on this basic insight, in this paper we estimate and review various joint econometric models using the Swedish National Commodity Flow surveys. Robust parameter estimates from this exercise will be used to update the current deterministic Swedish national freight model system (the SAMGODS model) to a stochastic one.
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| 13. |
- Abate, Megersa, et al.
(författare)
-
The optimal shipment size and truck size choice : The allocation of trucks across hauls
- 2014
-
Ingår i: Transportation Research Part A. - : Elsevier BV. - 0965-8564 .- 1879-2375. ; 59, s. 262-277
-
Tidskriftsartikel (refereegranskat)abstract
- There has been a growing interest in understanding how firms allocate their trucks across hauls, and how this allocation changes under various economic environments. This study investigates how variations in route/haul, carrier and vehicle characteristics affect the optimal vehicle size choice and the associated choice of shipment size. We show that the two choices are derived from the same optimization problem. There can be a continuum of shipment sizes, but decision-makers in freight transport have to choose from a limited number of vehicle alternatives. Therefore, we use a discrete-continuous econometric model where shipment size is modeled as a continuous variable, and vehicle size/type choice as a discrete variable. The results indicate that when faced with higher demand, and during longer trips firms are more likely to use heavier vehicles and ship in larger quantities which suggest that firms are realizing economies of scale and economies of distance. The study also discusses the effect of vehicle operating cost on the vehicle selection process and its policy implications.
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| 14. |
- Abbas, Khaled A, et al.
(författare)
-
A generic approach for in depth statistical investigation of accident characteristics and causes
- 2001
-
Ingår i: Proceedings of the conference Traffic Safety on Three Continents. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 653-665
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The main aim of this research is to develop a generic approach for the utilization of statistical methods to conduct depth investigation of road accident characteristics and causes. This approach is applied in an effort to analyse the 1998 accident database for the main rural roads in Egypt. This database is composed of traffic accident data collected for 14 road sections representing nine major roads of the Egyptian rural road network. The proposed approach is composed of two main stages of analysis. Within each stage, several analytical steps are conducted. The first stage is mainly concerned with developing cluster bar charts, where different characteristics and causes of accidents are portrayed in relation to variations in the three main accident contributing factors, namely types of roads, vehicles and drivers. The second stage is concerned with conducting in-depth statistical analysis of the collected accident data. Within this stage, four levels of statistical investigations were conducted. These are meant to examine a number of issues.
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| 15. |
- Abbas, Khaled A
(författare)
-
Environmentally sustainable transport strategies : the way forward in metropolitan cities
- 2001
-
Ingår i: Proceedings of the conference Traffic Safety on Three Continents. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 780-791
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper is concerned with one of the three requirements of a sustainable transport system, namely the environmental dimension. It starts by presenting components and interactions of the transport and traffic systems using causal diagrams. Generic traffic problems are identified and their causes categorized. A classification of demand and supply-based policies and measures that can be used in designing environmentally sustainable transport strategies is depicted. Such strategies are targeted towards minimizing the generic traffic problems encountered in metropolitan cities, i.e., traffic congestion, accidents, environmental degradation and energy inefficiencies. In this paper, Travel Demand and Land Use Management are considered as two of the basic pillars for designing environmentally sustainable transport strategies. Criteria for comparing demand versus supply-based policies are suggested. These are applied to assess the benefits and limitations of each policy, hence assisting decision makers in the prioritization and choice of such policies.
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| 16. |
- Abdallah, Clement Kamil, et al.
(författare)
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Assessing the quality of water used for vegetable irrigation in Tamale Metropolis, Ghana
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- This paper assesses water quality that is used for vegetable irrigation in Tamale Metropolis, Ghana. A mixed-method of research design was employed in this study to collect and analyze the data based on survey instruments. The paper found that Escherichia coli (E. coli) that is usually used as an indicator of water contamination and heavy metals exist in all taken water samples. The mean concentrations of nutrients such as ammonia, nitrate, nitrite and phosphate were recorded as 0.022 mg/l to 5.98 mg/l for ammonia, 1.06 mg/l to 7.52 mg/l for nitrate, 0.031 mg/l to 0.056 mg/l for nitrate and 0.037 mg/l to 0.069 mg/l for phosphate. E. coli and Total Coliforms levels for Sanghani, Kamina and Waterworks from the laboratory analysis were recorded as 3.2x10(3) CFU 100 m/l and 5.5x10(2) CFU 100 m/l, 4.0x10(3) CFU 100 m/l and 1x10(2) CFU 100 m/l, and 2.1x10(3) CFU 100 m/l and 4.6x10(2) CFU 100 m/l respectively. To conclude, based on the measured parameters, water used for irrigation in the Tamale Metropolitan is polluted and may cause potential health risks. Therefore, farmers, traders and consumers need to apply further safety measures to make the vegetables safe.
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| 17. |
- Abdel-Aty, M A, et al.
(författare)
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Developing crash predictive models for a principal arterial
- 2000
-
Ingår i: Proceedings of Traffic Safety on Two Continents. Conference in Malmö, Sweden, September 20-22, 1999. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 179-194
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 18. |
- Abdel-Aty, MA, et al.
(författare)
-
Using GIS to locate the high risk driver population
- 2000
-
Ingår i: Proceedings of Traffic Safety on Two Continents. Conference in Malmö, Sweden, September 20-22, 1999. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 111-126
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 19. |
- Abed, Ahmed, et al.
(författare)
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Uncertainty analysis of life cycle assessment of asphalt surfacings
- 2024
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Ingår i: International Journal on Road Materials and Pavement Design. - : Taylor & Francis. - 1468-0629 .- 2164-7402. ; 25:2, s. 219-238
-
Tidskriftsartikel (refereegranskat)abstract
- The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data, deterministic solution, and asphalt durability. This framework was applied to six asphalt mixtures; the results show that there is significant uncertainty in the processes that contribute to the environmental impacts. They also showed that considering asphalt durability and its uncertainty is critical and can significantly change the results and interpretation of LCA.
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| 20. |
- Abenoza, Roberto F., et al.
(författare)
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What is the role of weather, built-environment and accessibility geographical characteristics in influencing travelers’ experience?
- 2019
-
Ingår i: Transportation Research Part A. - : Elsevier Ltd. - 0965-8564 .- 1879-2375. ; 122, s. 34-50
-
Tidskriftsartikel (refereegranskat)abstract
- We examine the effect of weather, accessibility and built-environment characteristics on overall travel experience as well as the experience with the latest trips. These are factors that are often disregarded in the travel satisfaction literature even though they are believed to largely influence the first mile of the door-to-door trip. This study fills a research gap in investigating all these factors by using, amongst other, a relatively large travel satisfaction survey from years 2009 to 2015 and by focusing on urban and peri-urban geographical contexts, the city and county of Stockholm (Sweden), respectively. The ordered logit model results show that county dwellers living close to a metro station and in well linked-to-all areas report higher overall travel satisfaction evaluations. In addition, precipitation and ground covered with snow have a negative influence on travel satisfaction. Our findings indicate that built-environment characteristics exert a rather weak influence on the travel experience, especially in the peri-urban context. However, some aspects such as living in areas with medium densities, low income and with high safety perceptions around public transport stations are associated with higher satisfaction levels. In turn, areas with single land uses are found to have lower travel satisfactions. These results are important for public transport planners and designers in devising measures to prevent and mitigate the negative outcome of some weather conditions and to conceive better designed transit oriented developments.
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| 21. |
- Abou-Senna, Hatem, et al.
(författare)
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A methodology to quantify pedestrian crash rates against statewide averages for roadways and intersections
- 2016
-
Konferensbidrag (refereegranskat)abstract
- To date there are no clear or uniform standards for a method to measure pedestrian crash rates and compare it against a statewide average. In this paper, a novel methodology to measure pedestrian crash rates along roadways and intersections were quantified. The main objective is to identify critical pedestrian crash locations that are operating above its corresponding statewide average. It was crucial to address the pedestrian-vehicular conflict as the State of Florida currently tops the list in the “Dangerous by Design” report as having the highest four pedestrian incident locations in the Country. The main challenge was to identify a practical and correct exposure measure. In most cases, the exposure measure is either unavailable or can be obtained at a greater cost. The methods and procedures explained in this paper are considered detailed, practical and provide a broad depiction of the main factors that directly contribute to pedestrian crashes. The main parameters used in calculating pedestrian crash rates along roadways included functional classification, number of lanes, area type, AADT and the total length of the roadway category. Conversely, main parameters for computing pedestrian crash rates for intersections included daily pedestrian volumes, distance crossed and the AADT in addition to the number of pedestrian crashes either along the studied roadways or intersections. The pilot studies conducted for the roadways and intersections revealed several critical safety locations within District 5 when compared to the developed statewide average rates which required further investigation to identify main causes and emphasize mitigation improvements.
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| 22. |
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| 23. |
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| 24. |
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| 25. |
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| 26. |
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| 27. |
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| 28. |
- Abtahi, Farhad, et al.
(författare)
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Association of drivers’ sleepiness with heart rate variability : A pilot study with drivers on real roads
- 2018
-
Ingår i: IFMBE Proceedings. - Singapore : Springer Verlag. - 9789811051210 ; , s. 149-152
-
Konferensbidrag (refereegranskat)abstract
- Vehicle crashes lead to huge economic and social consequences, and one non-negligible cause of accident is driver sleepiness. Driver sleepiness analysis based on the monitoring of vehicle acceleration, steering and deviation from the road or physiological and behavioral monitoring of the driver, e.g., monitoring of yawning, head pose, eye blinks and eye closures, electroencephalogram, electrooculogram, electromyogram and electrocardiogram (ECG), have been used as a part of sleepiness alert systems.Heart rate variability (HRV) is a potential method for monitoring of driver sleepiness. Despite previous positive reports from the use of HRV for sleepiness detection, results are often inconsistent between studies. In this work, we have re-evaluated the feasibility of using HRV for detecting drivers’ sleepiness during real road driving. A database consists of ECG measurements from 10 drivers, driving during morning, afternoon and night sessions on real road were used. Drivers have reported their average sleepiness level by using the Karolinska sleepiness scale once every five minutes. Statistical analysis was performed to evaluate the potential of HRV indexes to distinguish between alert, first signs of sleepiness and severe sleepiness states. The results suggest that individual subjects show different reactions to sleepiness, which produces an individual change in HRV indicators. The results motivate future work for more personalized approaches in sleepiness detection.
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| 29. |
- Achit, Hamza, et al.
(författare)
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Physical Impairment and Medical Care Spending by Road Accident Victims
- 2013
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Ingår i: Proceedings of the 16th International Conference Road Safety on Four Continents. - Linköping : Statens väg- och transportforskningsinstitut.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In addition to the immediate physical injuries they suffer, road accident victims may also be subject to ongoing deterioration of their state of health in terms of permanent physical and mental problems, disabilities, etc. These various health shocks entail recourse to care and treatment, the upshot being increases in health expenses. In France little is known about the financial impact of accidents on victims. This paper uses data from a sample of 777 individuals suffering from road accident-induced physical impairment. Information about these individuals includes details of their personal and socioprofessional characteristics, together with data provided by their health insurance offices regarding their use of treatment and their medical expenses. The analysis of these data reveals that the costs incurred by road accident victims are significantly associated with such factors as age, seriousness of impairment, and marital status. Interaction effects are also noted between these explanatory factors: for example, the effect of the seriousness of impairment on the costs involved differs according to the age of the victim.
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| 30. |
- Achwan, Nawawi, et al.
(författare)
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Application and development of road safety audit in Indonesia
- 2001
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Ingår i: Proceedings of the Conference Road Safety on Three Continents in Pretoria, South Africa, 20-22 September 2000. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 107-115
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The high rate of road accidents in Indonesia have become a national problem, which need serious handling. One of the causes, beside the human and vehicle factor, is the road and environmental factor. Based on international research, the contribution of road and environmental factors is calculated to 24 %. This in turns stresses the importance of a strategy, which in the end lead to the improvement of road safety conditions through application of a road safety concept. The author strongly argues in favour of Road Safety Audits. A safety audit process could be applied at all stages - in the feasibility study before the road is constructed or rehabilitated, during all of the design phases and after the road have been in operation. Furthermore, this paper introduces the concept of road safety audit with an existing by pass road in Cirebon as an example.
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| 31. |
- Adell, Emeli, et al.
(författare)
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Cyclists' use of mobile IT in Sweden : usage and self-reported behavioural compensation
- 2014
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Ingår i: 3rd International Cycling Safety Conference (ICSC2014), 18-19 November, Gothenburg, Sweden. - Gothenburg, Sweden.
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Konferensbidrag (refereegranskat)abstract
- The increasing use of mobile phones while cycling has raised safety concerns. In this paper two studies of mobile phone use by cyclists are presented.The first study was designed to characterize mobile phone use by cyclists in Sweden, while the second studied how mobile phone use affected cyclist behaviour and compensation strategies. Mobile phone use was observed in about 20 percent of all urban bicycle trips. The usage varied with cyclist age with the highest usage among young cyclists. Of those using phones, 90% of the cyclists observed used head-phones.In parallel, standardized, interviews 15% of cyclists under 15 years old stated that they always used mobile phones while cycling. Listening to music in headphones was the most fre-quent self-reported activity. To converse using hand-held phones was also rather common, and was the only mobile phone usage reported by women above 50 years old.In the second study twenty-two young cyclists (age 16-25 years) completed a route in real traffic five times while listening to music, receiving and making calls, receiving and sending text messages, searching for information on the internet and while cycling normally without using the phone. The route and the types of tasks were controlled, but the cyclists could choose rather freely when, where and how to carry out the tasks. When the cyclist returned to the starting point, a short interview was conducted. During the interviews cyclists reported their experiences and the compensation strategies they used while cycling.
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| 32. |
- Adell, Emeli, et al.
(författare)
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Exponering av oskyddade trafikanter med hjälp av app-baserade resvaneundersökningar
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 287-288
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Trafiksäkerhetsarbetet har kommit långt i Sverige, men det finns stora utmaningar kvar vad gäller oskyddade trafikanters trafiksäkerhetssituation. Trafiksäkerhetsrisken baseras på antalet olyckor eller personskador per trafikant, trafikarbete eller annat exponeringsmått. För oskyddade trafikanter är dock förståelsen av exponering begränsad och det finns generellt ett behov av bättre förståelse för oskyddade trafikanters exponering i termer av reslängder, tid i olika trafikmiljöer.Samtidigt som kunskapsläget kring skyddade trafikanters exponering i allmänhet är låg ger ökad digitalisering nya sätt att förstå människors resvanor och användning av trafiksystemet. I app-baserade resvaneundersökningar används positioneringsdata från mobiltelefonen, vilket kan ge värdefull information om exponering men också annan trafiksäkerhetsrelevant information, så som hastigheter.Denna studie har undersökt om data från app-baserade resvaneundersökningar kan använts för att ge värdefull information om a) den oskyddade trafikantgruppen, b) exponering och c) annan trafiksäkerhetsrelevant information. Underlaget har varit en kommunal app-baserad resvaneundersökning. Fokus har varit cyklister. Positioneringsdata har knutits till infrastrukturen via map-matching mot en geografisk databas. Genom detta kan typ av infrastruktur (till exempel gång- och cykelvägnät) och infrastrukturens olika egenskaper (till exempel hastighetsgränser) knytas till varje enskild del av en resa. Hastigheter har beräknats hjälp av GPS-positionering och tidsangivelser utmed hela resans sträckning. Vi har i denna studie valt att beräkna hastigheter på 50-meterssektioner, vilket bedöms ge en bra bild över hastighetsprofilen över resan.Det är med hjälp av data från app-baserad resvaneundersökning möjligt att beskriva hur mycket olika typer av individer cyklar, både i antal resor, reslängd och restid, både totalt och fördelat över dygnet. Den geografiska informationen gör det dessutom möjligt att förstå i vilken trafikmiljö som resor sker. I denna studie har vi analyserat hur mycket av transportarbetet som skett på olika typer av infrastruktur, vilket kan ställas i relation till var olyckor och skador skett för att beräkna trafiksäkerhetsrisker på olika typer av infrastruktur. I detta fall har vägtyp och hastighetsgräns använts, men det skulle också kunna vara typ av korsning om den data finns tillgänglig i den digitala beskrivningen av infrastrukturen.
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| 33. |
- Adell, Emeli, et al.
(författare)
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How Is Acceptance Measured? : Overview of Measurement Issues, Methods and Tools
- 2014
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Ingår i: Driver Acceptance of New Technology. - Farnham, Surrey, England : Ashgate. - 9781409439844 ; , s. 74-88
-
Bokkapitel (refereegranskat)abstract
- This chapter describes how acceptance has been measured and identifies various measurement categories. The relationship between these measurement methods and the different definitions of acceptance appearing in the literature is described and the lack of correspondence between definition and measurement is highlighted. The chapter illustrates the different outcomes of acceptance measurements depending on choice of assessment method and gives some guidance that could be used depending on the purpose of the assessment.
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| 34. |
- Adell, Emeli, et al.
(författare)
-
Investigating untapped bike potential with crowdsourcing data
- 2024
-
Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 488-489
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The city of Lund has a high share of trips done by bicycle, and ambitious goals of becoming climate-neutral by 2030. Still the municipality, like many other cities, has difficulty in reaching the goals of increasing cycling and needs to find the real potential. To understand the untapped cycling potentials of a city, and generally to promote it, it is important to first assess how bike is used and why. This can be done by observing the bike flows and understanding the reasons for the use or misuse of bikes as a transport mode. Particularly, for the scope of identifying untapped potential, the preferred time scale should be smaller than the traditional count based on annual average figures. Also, opposite to motorized traffic, bicycle volume can rapidly change inside a city. All this caused the need to search for more effective methods to estimate bicycle volume like crowdsourcing data that can be provided by mobile apps which are usually collected for other purposes. The present study introduces a method of bicycle volume estimation based on GPS data from the TravelVu application, an app-based tool to collect travel survey data. A spatial analysis has been chosen to investigate the correlation between the data from the Lund municipality counting and the GPS data from TravelVu app. The analysis has been performed by comparing the average daily bike volume with the aggregated data in 3 months for the GPS track. Counting data refers to 2018 and 2021 and the TravelVu data refers to 3 months starting from August 2018 and 2021, where 2018 data are collected through crowdsourcing and 2021 are random sampling. All the weekend data have been removed since the manual counting was always carried out during weekdays (and should be represented by those). At first, all the data from the Lund municipality report were digitalized in a GIS map and then clustered per intersection to have a more robust regression when compared to the TravelVu data and to reduce the possible spatial errors.
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| 35. |
- Adell, Emeli, et al.
(författare)
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Modelling Acceptance of Driver Assistance Systems : Application of the Unified Theory of Acceptance and Use of Technology
- 2014
-
Ingår i: Driver Acceptance of new technology. - Farnham, Surrey, England : Ashgate. - 9781409439844 ; , s. 23-34
-
Bokkapitel (refereegranskat)abstract
- This chapter provides a brief overview of acceptance models used within the area of information technology. One particular model, the Unified Theory of Acceptance and Use of Technology (UTAUT), is then discussed, and a study is reported in which the model was used to assess driver acceptance of a particular driver assistance system. The key findings of that study are reported, and suggestions are made for refining UTAUT to make it more suitable for assessing acceptance of driver assistance systems.
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| 36. |
- Adell, Emeli, et al.
(författare)
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The Definition of Acceptance and Acceptability
- 2014
-
Ingår i: Driver Acceptance of New Technology. - Farnham, Surrey, England : Ashgate. - 9781409439844 ; , s. 11-21
-
Bokkapitel (refereegranskat)abstract
- Despite the recognised importance of the concept of acceptance, how and why new technologies are actually accepted by drivers is not well understood. While many studies claim to have measured acceptance, few have explicitly defined what it is. This chapter points out the importance of defining acceptance and categorises definitions that have been used according to their “essence”. Distinctions between different types of acceptance as well as between acceptance and acceptability are also described. A proposal for a common definition of acceptance is then presented and discussed.
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| 37. |
- Adesiyun, Adewole, et al.
(författare)
-
Overview of connected and automated driving test sites
- 2020
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Ingår i: Proceedings of 8th Transport Research Arena TRA 2020. ; , s. 7-
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Konferensbidrag (refereegranskat)abstract
- Connected and automated vehicles potentially offer solutions to some key challenges for National Road Administrations (NRAs), such as reduction of accidents, increasing network capacity etc. As a result of this potential, both industry and certain national governments are undertaking trials that are mainly focused on technological challenges such as the ability of vehicles to drive safely in “random” situations etc. Far less attention has been paid to questions around the implications for NRAs. The overall aim of the STAPLE project is to provide a comprehensive review of technological and non-technological aspects of the most relevant connected and automated driving test sites in order to understand the impact of these sites on the NRAs’ core business and functions.
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| 38. |
- Adesiyun, Adewole, et al.
(författare)
-
Review and Evaluation of NRAs : Deliverable D2
- 2023
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Connected and Automated Driving (CAD) is an important area of digital technology that will bring disruption to individuals, economies, and societies. Most forms of CAD require some level of infrastructure support for their safe operation. Additional infrastructure and services to support CAD have the potential to improve safety even further, and to bring other benefits such as increased efficiency or reduced congestion. However, the infrastructure requirements from Original Equipment Manufacturer (OEMs) are not always clear, and it is difficult for National Road Authorities (NRAs) to predict and plan for the future levels of support needed for CAD given rapidly evolving technology and uncertain projections of future CAD demand. In addition, there is also a need for better dialogue among NRAs, OEMs and service providers to articulate those requirements and to define a roadmap and responsibilities for achieving safe and smart roads through CAD.The aim of DiREC is to establish a CAV Readiness Framework and a set of toolkits dedicated to CAVs (Connected and Autonomous Vehicles) that incorporates a wide range of components that affect CAD and the ability of highway infrastructure to support it. These components include machine readability of physical infrastructure, digital services, connectivity, in addition to aspects such as governance of the infrastructure and services, and legal and regulatory requirements. Together these components influence the ability of the NRA to become a digital road operator. The DiREC project will thus provide a framework for NRAs, service providers and OEMs to support CAD. It will consolidate and combine standards, research, and recommendations from other projects and extend research into new areas such as creating a common vision for digital twins among NRAs, understanding connectivity and connectivity requirements to support digital services and analysing how these can be met, reviewing the quality management processes around digital data, and documenting existing legal and regulatory frameworks in all areas relating to CAD.
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| 39. |
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| 40. |
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| 41. |
- Adolehoume, Amakoe, et al.
(författare)
-
Road safety policies in seven West African countries
- 2001
-
Ingår i: Proceedings of the Conference Road Safety on Three Continents in Pretoria, South Africa, 20-22 September 2000. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 303-316
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- At the end of 1999, UEMOA, the Economic and Monetary Union for West Africa, launched a study of the road safety situation and management processes in seven of the eight countries of the Union (Benin, Burkina Faso, Cite d'Ivoire, Mali, Niger, Senegal, Togo), in view of formulating Communal Road Safety Policies at the regional level. A team of African and European "experts" was formed to establish a diagnosis on each country as well as a global assessment of the situation in the region, and to draw proposals for action. The final report was published in March 2000 and is now being evaluated by UEMOA and integrated into a wider proposal for transport policies, for presentation at a round table of donors. The present paper does not provide a complete summary of the outcome of the study, but presents a selection of some difficult problems encountered in the countries investigated and directions for possible solutions as seen by the researchers and consultants that took part in the study. Comprehensive proposals and guidelines for Communal Road Safety Policies are not included as they have not officially been accepted by UEMOA yet, but the original report can be requested from this organisation in Ouagadougou. A brief outline of the approach and methodology used is described. More complete methodological guidelines, developed from the experience gathered through the UEMOA study as well as previous ones carried out by Inrets (the French National Institute for Transport and Safety Research) will be published at a later stage.
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| 42. |
- Adolph, Thorsten, et al.
(författare)
-
Comparison of the dummy response in two different restraint system crash tests
- 2014
-
Ingår i: 2014 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury. ; , s. 545-561
-
Konferensbidrag (refereegranskat)abstract
- In the European Project FIMCAR, a proposal for a frontal impact test configuration was developed which included an additional full width deformable barrier (FWDB) test. Motivation for the deformable element was partly to measure structural forces as well as to produce a severe crash pulse different from that in the offset test. The objective of this study was to analyse the safety performance of vehicles:in the full width rigid barrier test (FWRB) andin the full width deformable barrier test (FWDB)In total, 12 vehicles were crashed in both configurations. Comparison of these tests to real world accident data was used to identify the crash barrier most representative of real world crashes. For all vehicles, the airbag visible times were later in the FWDB configuration. This was attributed to the attenuation of the initial acceleration peak, observed in FWRB tests, by the addition of the deformable element. These findings were in alignment with airbag triggering times seen in real world crash data. Also, the dummy loadings were slightly worse in FWDB compared to FWRB tests, which is possibly linked to the airbag firing and a more realistic loading of the vehicle crash structures in the FWDB configuration. Evaluations of the lower extremities have shown a general increasing of the tibia index with the crash pulse severity.
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| 43. |
- Adolph, T., et al.
(författare)
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Development of compatibility assessments for full-width and offset frontal impact test procedures in FIMCAR
- 2014
-
Ingår i: International Journal of Crashworthiness. - : Informa UK Limited. - 1358-8265 .- 1754-2111. ; 19:4, s. 414-430
-
Tidskriftsartikel (refereegranskat)abstract
- The goal of the project FIMCAR (Frontal Impact and Compatibility Assessment Research) was to define an integrated set of test procedures and associated metrics to assess a vehicle's frontal impact protection, which includes self-And partner-protection. For the development of the set, two different full-width tests (full-width deformable barrier [FWDB] test, full-width rigid barrier test) and three different offset tests (offset deformable barrier [ODB] test, progressive deformable barrier [PDB] test, moveable deformable barrier with the PDB barrier face [MPDB] test) have been investigated. Different compatibility assessment procedures were analysed and metrics for assessing structural interaction (structural alignment, vertical and horizontal load spreading) as well as several promising metrics for the PDB/MPDB barrier were developed.The final assessment approach consists of a combination of the most suitable full-width and offset tests. For the full-width test (FWDB), a metric was developed to address structural alignment based on load cell wall information in the first 40 ms of the test. For the offset test (ODB), the existing ECE R94 was chosen. Within the paper, an overview of the final assessment approach for the frontal impact test procedures and their development is given.
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| 44. |
- Afridi, Amjad, et al.
(författare)
-
Management of municipal street network in Sweden : results from a national survey
- 2024
-
Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 395-396
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Management of street networks is different from state roads due to its multifunctional role in society. This requires timely maintenance of the street network to improve socioeconomic development. Municipalities in Sweden are responsible for the management of about 42000 km of street network in their jurisdiction. Maintenance budget and resources vary from municipality to municipality depending on their network size, geographical location, and population density. A questionnaire was sent to all 290 municipalities across the country to investigate the street network and pavement management practices at the municipal level. An in-depth interview of 14 municipalities took place afterwards. A total of 51% of responses were officially received to highlight the frequently and infrequently occurring pavement distresses and their causes. Furthermore, the study highlights the maintenance approaches and allocation of budget to manage the street network. Lastly, the study highlights the factors which need to be addressed to improve street network management. Visual assessment of pavements is common and the use of pavement management system (PMS) is not only limited but also lacks pavement performance prediction models. Common pavement distresses are excessive formation of potholes, surface unevenness and alligator distress among the municipalities. Frequent causes of distress include the ageing of the street network, heavy vehicles, patching and high traffic flow. Furthermore, cold climate and population density are important factors in the degradation process. Allocation of maintenance and reconstruction budget is relatively high in municipalities located in the north. Densely populated municipalities have higher taxpayers’ contributions to maintenance and reconstruction. Other major issues are limited resources and maintenance of budget, which adversely affect the maintenance backlog and the choice of maintenance alternatives, ultimately the decision-making. This restricts the use of preventive maintenance among the municipalities. Municipalities are required to improve the frequency and quality of pavement data collection, enhance the sophistication of PMS by using pavement deterioration models, and increase the maintenance budget and resources. An insight into the capabilities of municipalities would help in long-term strategic planning and effective utilisation of the maintenance budget to improve the street network across the country.
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| 45. |
- Afridi, Muhammad Amjad, et al.
(författare)
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Municipal street maintenance challenges and management practices in Sweden
- 2023
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Ingår i: Frontiers in Built Environment. - : Frontiers Media S.A.. - 2297-3362. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The municipal street network acts as a multifunctional asset by providing people, vehicles and public services with a well-functioning infrastructure. To keep it in good condition, optimal maintenance measures are required which would result in an efficient use of taxpayers' money. This paper investigates the street network deterioration processes and the management practices that the municipal administrations have applied in Sweden. The study is based on a survey with Swedish municipalities using questionnaires and complementary interviews. The answers provide insight into a wide range of common pavement distresses and deterioration factors, along with pavement management practices. The study identifies that potholes, surface unevenness and alligator cracking are the most cited challenges, while pavement ageing, heavy traffic and patches are the most noted causes. Similarly, the cold climate and population density are influential factors in pavement deterioration. Allocation of the maintenance and rehabilitation and reconstruction budget is higher in the northern part of the country as well as in densely populated municipalities. Condition data collection and use of commercial Pavement Management Systems (PMS) are limited. Addressing the challenges effectively may be possible through the enhancement of the budget, feasible/clear guidelines from municipal councils/politicians, and reducing the gap between street network administrations and utility service providers.
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| 46. |
- Agebjörn, Anika
(författare)
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Transportforskningen som populärvetenskap
- 1991
-
Ingår i: VTI:s och TFB:s forskardagar. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 131-135
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 47. |
- Agustsson, Larus
(författare)
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Automatic speed control : The Danish pilot project
- 2001
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Ingår i: Proceedings of the conference Traffic Safety on Three Continents. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 497-503
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The goal of the new Danish Road Safety Action Plan is to reduce the number of traffic accident fatalities and serious casualties by 40% from 1998 to the year 2012. This plan is ambitiously titled "Each Accident is One Too Many". The four main areas of the accident plan are accidents caused by speeding, accidents caused by intoxicated drivers, accidents with bicyclists, and accidents at intersections. This paper deals with the first type of accident in the plan - accidents caused by speeding. Specifically, the paper describes the automatic speed control pilot project in Denmark.
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| 48. |
- Agustsson, Larus
(författare)
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Danish experiences with speed zones/variable speed limits
- 2001
-
Ingår i: Proceedings of the conference Traffic Safety on Three Continents. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 793-804
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The first Danish Road Safety Action plan in 1989 reduced the number of fatalities and casualties by 30% by the year 2000. The goal of the new Danish Road Safety Action Plan is to reduce the number of fatalities and serious casualties by 40% from 1998 to the year 2012. One of the actions that will be used to actuate this plan is the implementation of speed management and speed zones. This paper discusses the Danish experience with speed zones and variable speed limits.
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| 49. |
- Ahlberg, Joakim, 1966-, et al.
(författare)
-
Ad hoc-processen : hur används ledig kapacitet i järnvägsnätet?
- 2016
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Efter Trafikverkets fastställelse av nästkommande års tågplan i mitten av hösten varje år vidtar den så kallade ad hoc-processen, det vill säga ansökningar om tåglägen som kan använda ledig kapacitet i järnvägsnätet. VTI fick i september 2015 Transportstyrelsens uppdrag att fördjupa förståelsen av ad hoc-processen. Detta notat avrapporterar uppdraget.Mot bakgrund av den beskrivning som görs har avsikten varit att också hitta mått på betydelsen av denna process i förhållande till den process som leder fram till att en färdig tidplan läggs fast. Det har emellertid visat sig att Trafikverkets olika system för informationshantering inte är utformade för att möjliggöra en sådan beskrivning. Tack vare ett nyligen offentliggjort statistikhjälpmedel är det emellertid möjligt att konstatera att närmare 97 procent av de persontåg som bokats i den ordinarie processen också faktiskt körs. Denna uppgift avser två tredjedelar av tidtabellåret 2015. Avsikten från Trafikverket/Trafikanalys är att inom en nära framtid också redovisa motsvarande information om godstrafiken.Bakom denna siffra döljer sig emellertid både ett utflöde från, och ett inflöde till den mängd trafik som ska bedrivas i enlighet med den tidtabell som fastställs under hösten varje år. Det saknas emellertid kunskap om när dessa förändringar genomförs, vilket är av stor betydelse för att bedöma graden av flexibilitet i ad hoc-processen. Denna situation kan komma att förändras som ett resultat av att Trafikverket från och med den tidtabell som avser 2016 inför avgifter för att avboka tilldelad kapacitet. Avgiften blir högre ju närmare det planerade tågets avgång som ansökan tas tillbaka. Detta kan bidra till en förbättrad flexibilitet i användningen av den spårkapacitet som inte reserveras i den ordinarie tidtabellsläggningsprocessen. Ytterligare en konsekvens kan bli att informationen om processen förbättras.
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| 50. |
- Ahlberg, Joakim
(författare)
-
Analysis of discrete multi-unit, common value auctions : a study of three sealed-bid mechanisms
- 2012
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- This paper proposes a discrete bidding model for both quantities and pricing. It has a two-unit demand environment where subjects bid for contracts with an unknown redemption value, common to all bidders. Prior to bidding, the bidders receive private signals of information on the (common) value. The value and the signals are drawn from a known discrete affiliated joint distribution. The relevant task for the paper is to compare the equilibrium strategies and the seller’s revenue of three auction formats. We find that, of the three auctionformats below with two players, the discriminatory auction always gives the largest revenue to the seller; both the uniform and the Vickrey auction have zero revenue equilibrium strategies that put them further down in the revenue ranking. In equilibrium, bidders bid the same amount on both items in the discriminatory auction; a phenomenon not noted in either of the other auction formats.
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