Change search
Refine search result
1234567 1 - 50 of 1700
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aassi, Adil
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Drift och underhåll för högre effektivitet av järnvägar.2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Den senaste svenska vintern var en riktig katastrof som bestod av Ovanliga mängder snö, fukt och kyla, från mitten av december 2009 till mitten av mars 2010. Snömassor orsakade stora problem i tågtrafiken, både nationellt och lokalt. Det påverkade både gods- och persontransporten. Halka och tak ras ledde till personskador och dödsolyckor. Kylan påverkade även elnät som ledde till att människor stod utan värme och belysning. Allmänheten drabbades av snöovädret på olika sätt. Människor skadades i trafiken, halkolyckor, och flera tak som rasade ner. Människor kom även försent till olika destinationer. I södra och mellersta Sverige var problemet störst inom området transport (väg, järnväg). Störningar i vatten, elförsörjningen och tak ras. I söder uppstod ett kontaktledningsfel med flera växel- och signalproblem.

    En viktig sak är att det inte går att tänka att den vintern bara var en engångsföreteelse, utan Trafikverket måste tänka på att Sverige ligger i Norden och att vintern 2009/10 kan upprepas flera gånger. Därför är det viktigt att bygga en modell för underhållet. Trafikverket skulle kunna ta de sista vintrarna på allvar och ta fram en åtgärdsplan för att minska effekterna av framtida, svåra vinterförhållanden.

    Avhjälpande åtgärder måste då sättas in snabbt för att förhindra störningar i trafiken. Mången tågtrafik störningar beror på fel i någon eller några komponenter som själva baninfrastrukturen består av. En jämförelse har gjorts mellan spårväxlar under sommaren och spårväxlar under vintrar, som visar 85 % fler fel under vintertid än sommartid. Trafikverkets kostnader för underhåll av järnvägar på lång sikt uppgår till 4 miljarder. Regeringen fastställde den nya nationella trafikplanen för utveckling av transportsystemet för perioden 2010-2021 i slutet av mars 2010. I arbetet undersöks en jämförelse, så kallad "Benchmarking" mellan Sverige och Schweiz som visar hög kvalitet i kapacitetsutnyttjande och hög punktlighet i Schweiz. Punktlighet i Schweiz har stigit 97 % medan i Sverige var 87 %.

    Ett övergripande syfte med arbetet är att undersöka hur effektiviteten på det svenska järnvägs nätet kan förbättras genom att studera framgångarna i Schweiz.

  • 2.
    Abayneh Alembo, Zinash
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    User delay costs and uncertainty in the traffic forecast for road projects.2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    There are experimental based software packages as well as traffic simulation models that

    are used for analyzing life cycle cost of road projects. Among those our study was focused on

    currently available models to analyze the road user delay costs and to identify factors

    affecting road user delay costs. Sensitivity analyses were performed to identify the important

    factors that influence the user delay cost. Finally, prediction of future traffic demand as well

    as user delay cost, using the binomial lattice model, were presented to include the uncertainty

    of future traffic and user delay costs. The results of this study could help the highway

    designers with evaluating the future traffic.

  • 3.
    Abdi, Adel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Efficient Winter Road Maintenance: A Study of Technical and Contractual Issues2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Since ancient times, roads have tied people and cultures together. Roads have been createdwith the aim of facilitating trade and cultural exchange among different regions in the world. After the technologic development in vehicle industry and dramatically increase of motoring in the world during the past century road communication has gained a great importance for transporting people and goods. Thus, good safety and accessibility on roads all year round is now a vital necessity for a healthy economy in all modern societies. In order to keep roads safe, available for use with high transport quality they need to be maintained in real time. One of the most difficult tasks in this context is to keep the roads in good condition and accessible even during winter. The main objective of this doctoral thesis is to attempt to specify the most efficient ways of executing winter road maintenance.  The preliminary issue in this context is whether it is the use of current assistive tools, that is, technical aspects that should be optimized and developed or whether it is the way in which winter maintenance services are procured and outsourced, that is, contractual aspects that should be improved which could give the optimal impact for both clients and contractors and make winter road maintenance more effective, or both issues. In order to define the outline of the research project a comprehensive state of the art survey was initiated with the intention of collecting and gaining insights into the earlier studies in the research area. Three basic areas associated with the performance of winter road maintenance were considered to be most relevant for review due to the anchorage between the areas. The selected areas were climatological, technical and contractual aspects. The literature review was followed by an electronic questionnaire survey. The results of the study in this stage showed that current technical methods almost functioned in a reasonable manner but there was an imprecise dissatisfaction with the current maintenance contract. The second stage of the research consisted of a number of additional empirical investigations in order to identify contractual problematic issues behind the current winter road maintenance in Sweden. Generally, those factors that are rarely considered as potential underlying causes to costly performance of winter road maintenance in Sweden were studied in this research project for example improper use of related technical assistive tools, procurement of improper bundled winter services and inappropriate contract structure. This thesis consists of six papers, five of which are related to each other, and the first one is completely independent but within research area. Findings in the thesis contributes to extend understanding about; how designing appropriate contracts can improve winter road maintenance, how proper use of assistive tools can reduce unnecessary winter road maintenance costs and minimize road traffic disruptions and delays, how a partnering structure in contracts can create confidence and trust between clients and contractors that in turn leads to minimizing or eliminating conflicts and disputes between parties involved, how choice of appropriate procurement methods through proper bundling of winter road services can contribute to shorten the procurement process and create incentives for contractors, and how selection of proper payment mechanisms can contribute to higher service quality of performed winter road measures. Additionally, an adequate knowledge and understanding of climate, proper knowledge of road weather and its impact on winter road traffic is essential for contribution of better planning of how to maintain the road network during winter. Since understanding about winter issues and its effect on winter road traffic is far from complete and winter road maintenance in the cold regions is a similar challenge, broad and complex, the results of this research may even contribute to improving winter maintenance problems in the countries with severe winters like Sweden.

  • 4.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Choice of Appropriate Tyres as an Asset to Traffic Safety on Winter Roads: Compilation and Evaluation of Some Winter Tyre Tests in Sweden2011In: International Journal of Civil & Environmental Engineering, ISSN 2077-1258, Vol. 11, no 6Article in journal (Refereed)
    Abstract [en]

    Winter tyres must be able to cope with the slipperiness which occurs on the surface of the roads during winter. The slipperiness is generated by water vapour in the atmosphere, precipitating and transforming into a solid form i.e. in ice form, either directly or after refrigeration or cooling. Many experimental studies e.g. winter tyre tests have been carried out by many companies and authorities independently from each other to determine if there are any types of tyres which have the best grip on different road surface conditions in the winter. The purpose of this study is to compile, analyse, compare and evaluate the obtained results of some winter tyre tests which have been performed in Sweden during years 2007-2010. The study aims further to find out which types of these tyres are most appropriate as an asset and increase the traffic safety on Swedish winter roads. Both studded tyres and non-studded tyres, socalled friction tyres or all season tyres were used in the tests. The method of the study is partly based on a theoretical study by reviewing some literature in this area and furthermore studying some practical cases i.e. winter tyre tests. The results of the tests are given in tables and figures showing the function of different types of the studded and nonstudded tyres on different road conditions. All test-tyres have been supplied by several tyre manufacturers. The study is only limited to compare the grip and effectiveness of different type of winter tyres on different kind of road conditions. The study does not take the impact of the tyres on the environment into consideration. The study shows that currently there are several types of winter tyres on the market but there is no tyre that is ideal or works best under all winter conditions.

  • 5.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Contract forms and agreements for operation and maintenance of highways and railways during winter2011Report (Other academic)
  • 6.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Key aspects in winter highway operation and maintenance2010Report (Other academic)
  • 7.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Technical and contractual aspects in winter highway and railway operation and maintenance: a survey of current technical systems and contract forms in Sweden2011Licentiate thesis, comprehensive summary (Other academic)
  • 8.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Designing appropriate contracts for achieving efficient winter road and railway maintenance with high performance quality: A survey of the state of practice in Sweden2014In: International Journal of Quality and Service Sciences, ISSN 1756-669X, E-ISSN 1756-6703, Vol. 6, no 4, p. 399-415Article in journal (Refereed)
    Abstract [en]

    Purpose - For a long time, the winter maintenance of the Swedish road and railway network had been performed in-house by Swedish Transport Administration, Swedish local authorities i.e. municipalities and Stockholm public transport. During the last 15 years the winter operation and maintenance of these state infrastructures have been performed by public procurement and contracting from independent contractors, where in practice the lowest price is the dominating selection criteria. The aim of this paper is to investigate and identify how these contracts are designed and how satisfied the parties are with the contract and the quality of the performed work during the winter and point our directions for improvement. Design/methodology/approach - The study was conducted by a literature review and followed by semi-structured interviews and electronic questionnaire. Findings - The results of the study which are based on the interviews and the online questionnaire show that there is widespread dissatisfaction with the contracts among both clients and contractors. Practical implications - The article prepares a basis showing how a contract affects the quality of the performed winter road and railway maintenance services. Originality/value - The findings lead to a number of suggestions about how to improve the contracts, e.g. having a separate winter maintenance contract to increase the quality of performed winter maintenance measures, a more partnering-like structure where consultations and adjustment can be made during the contract period. A partnering structure also makes it less important to get all the details right in the contract.

  • 9.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Effective Winter Highway Maintenance through Applicationof Partnering Concept2013In: International Journal of Engineering Management and Economics (IJEME), ISSN 1756-5154, E-ISSN 1756-5162, Vol. 3, no 3, p. 112-125Article in journal (Refereed)
    Abstract [en]

    Inmany countries winter road maintenance is outsourced to private contractors. Selecting appropriate contract for performance of winter highway maintenance and implementing it in an efficient way is then very important for both results and costs. Writing contracts concerning winter road maintenance is however difficult as weather conditions are hard to describe in an exact way and as what is rational to do in a certain situation, depends on expected future conditions. Problems during recent harsh winters in Sweden have clearly illustrated this. The study argues, with reference both to theoretical and empirical studies, that a partnering concept can improve efficiency in outsourced winter road maintenance. A detailed model of how partnering can be implemented is presented for winter road maintenance contracts together with systems for information supply such as International Roughness Index –surface unevenness measurement and Road Weather Information System.

  • 10.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Payment mechanisms for winter road maintenance services2013In: Australasian Journal of Construction Economics and Building, ISSN 1835-6354, Vol. 13, no 4, p. 18-31Article in journal (Refereed)
    Abstract [en]

    In countries with severe winters, a major portion of the annual budget for road maintenance is allocated to winter road maintenance. Thus it is important to identify an appropriate basis for the remuneration of the entrepreneurs who carry out the maintenance tasks, one that minimises or eliminates disputes and that satisfies both client organisations and contractors. The objective of this study is to investigate and evaluate the payment models applied in Sweden for winter road maintenance services and suggest possible improvements. Inadequate reimbursement models lead either to unnecessary cost overruns that affect the client's annual budget or cause cash flow problems for the contractor, which can result in safety issues. To solve the problems associated with paying for just-in-time road maintenance, cold region countries such as Sweden have developed various remuneration models, including some based on what is known as the Weather Index. The study uses a domestic questionnaire survey, analysis of a number of current contract documents, a series of meetings with project managers followed by an international benchmarking investigation. The study identified four winter maintenance remuneration models of which one is based on weather data. The study reveals that the payment model based on weather data statistics is applied only to roads with higher traffic flow and generates the most uncertainty about costs. Possible improvements should include more reliable weather data obtained from weather stations and bonuses related to customer satisfaction.

  • 11.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Public Procurement of Winter Road Maintenance Services Based on EU Procurement Directive: Lessons from Sweden2013In: Journal of Investment and Management, ISSN 2328-7721, Vol. 2, no 4, p. 70-86Article in journal (Refereed)
    Abstract [en]

    Public procurement of road maintenance services, particularly in cold regions is not an easy task in order to satisfy road-users during winter. Road-users’ dissatisfaction, complaint and pressure can usually be considered as major factors for having more accessible and safe roads during winter. These pressures have contributed and led to an increasing critical approach focusing on public procurement of these services after some harsh winters in the recent years in Sweden with traffic disruption and delay as consequence i.e. an increasing focus on the way in which the Swedish state authorities and local governments procure winter road maintenance services. The present study which is part of a larger research project investigating efficient winter road maintenance through procurement, tendering and contract aimed at extending this knowledge base with regard to procurement and socioeconomic factors with focus on the winter maintenance of the Swedish road network. The study reveals that even the Swedish winter road maintenance services are procured and outsourced in accordance with EU directive and public procurement rules transposed into the Swedish act on public procurement, the act has been interpreted in a manner that all the process has led to great dissatisfaction of end-users during winter due to improper bundling of winter related services. The lack of economic motivation in current contracts concerning winter road maintenance in the form of incentives has led to an inefficient performance of winter road measures. The study suggests a number of proposals in order to make forthcoming contracts more effective through proper bundling of winter services and create incentives for contractors to improve the performance of winter road maintenance services.

  • 12.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Use of Road Weather Information System (RWIS) as Assistive Tool for Effective Winter Road Maintenance: Technical andContractual Interactions2012In: International Journal of Engineering and Technolgy, ISSN 2049-3444, Vol. 2, no 12, p. 2002-2012Article in journal (Refereed)
    Abstract [en]

    Winter highway operation and maintenance in the northern periphery is a challenge, a broad and complex area. Understanding about this area and its effect on winter traffic performance is far from complete. During the last forty years since Swedish Transport Administration (former Swedish National Road Administration) began attempting of the use of Road Weather Information System -RWIS on the Swedish road network, the repair and maintenance methods of this assistive tool has dramatically changed. Changing of the methods have been due to the progress and development of the technology within this area i.e. from simple stations that could be connected via telephone network for icy road warning to amore sophisticated and modern internet based technology. The main objective of this study was to investigate and find the importance and effectiveness of using weather data collected from RWIS by road agencies as an assistive tool for effective performance of winter road maintenance, and how these tools are currently maintained without influencing the delay of winter road maintenance.The study also attempts to find possible interactions between technical and contractual issues that may affect winter road maintenance. The method of the study was partly based on a theoretical study by reviewing some internationally published articles and reports in this area and furthermore a domestic questionnaire survey, an internationalbenchmarking and a follow-up study within a selected region in Sweden. The results of the study reveal that even if the weather stations are normally placed on roads where the risk of icy roads is greatest, there are indirect factors which influence the planned maintenance of these tools which subsequenly cause delay of winter road maintenance.

  • 13.
    Abenoza, Roberto
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Ceccato, Vania
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Susilo, Yusak O.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Cats, Oded
    KTH, School of Architecture and the Built Environment (ABE), Transport Science. Department of Transport and Planning, Delft University of Technology, Delft, the Netherlands.
    Individual, Travel, and Bus Stop Characteristics Influencing Travelers’ Safety Perceptions2018In: TRR Journal of transportation research boardArticle in journal (Refereed)
    Abstract [en]

    Ensuring safety during door-to-door public transport trips is a fundamental challenge to service providers as safety influences individuals’ mobility. Using reported safety perceptions of travelers waiting at six bus stops with different characteristics in Stockholm, this study investigates factors that have an impact on determining travelers’ perceived safety and crime perceptions. This is done by assessing the importance of real-time information provision and the environmental characteristics of bus stops during the day and at night for different types of crime, after controlling for travelers’ individual and trip characteristics, and their previous experiences of victimization. Interaction effects of age, gender, and travel frequency are also tested. The  results  suggest  that  bus  shelter  characteristics,  natural  surveillance,  and  trustworthy  real-time  information  are  the most important factors influencing safety and crime perceptions. Additionally, safety perceptions are strongly influenced by previous experiences of victimization. The effect of perceived feelings about crime and safety are found to be nuanced by age and gender. Unlike some common beliefs, travelers: (1) feel less worried about becoming a victim of crime at bus stops associated with high crime rates; (2) prefer opaque shelters at night; and (3) have higher safety perceptions when the stop is located in an area of mixed land use. The impact of a bus stop’s number of passers-by is found to be insignificant. No direct or indirect effects can be attributed to frequency of travel by bus, indicating that familiar places and routine behavior have noeffect on declared crime and safety perceptions.

  • 14.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    The theory practice gap in regional (transport) planning2016In: RSA Annual Conference Graz 2016, Regional Studies Association , 2016Conference paper (Other academic)
  • 15. Ahlberg, J
    et al.
    Claesson, L
    Nauwelarts de Agé, M
    Näsman, P
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Relationen mellan upplevelsemått och fysiologiska mått på fysisk ansträngning1980In: Information från Psykotekniska institutet, ISSN 0347-2795, no 115Article in journal (Other academic)
  • 16.
    Ahmad Termida, Nursitihazlin
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Understanding Individuals' Learning and Decision Processes in a Changing Environment by Using Panel Data2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    When a new transport service is introduced, people have to learn and familiarize themselves with the new service before they decide to adopt it. These processes are developed over time, thus produce dynamics in individuals’ behavioural responses towards the service. This affects the demand of the new service, thus affect revenues. Available studies have examined the factors influencing these responses from microeconomic perspectives. The influence of the theory-based subjective factors has not been examined empirically. Understanding these would assist transport and urban planners to design a better marketing strategy to increase the market share of the new service. A change in seasons affect individuals’ activity-travel decisions, thus produce dynamics in activitytravel patterns in different seasons. Individuals’ constraints, in a form of mandatory activities (working/studying), are influencing individuals’ decisions to participate in day-to-day nonmandatory activities (leisure and routine activities). The interdependency between travel demand, time allocation and mode choice that considers interactions between mandatory and non-mandatory activities, in different seasons is less explored. Understanding these would assist transport planners and operators to manage travel demand strategies across different seasons of the year and provide better transportation systems for all individuals. This thesis includes five papers. Paper I explores individuals’ characteristics of the quick-response and the adopters of the new public transport (PT) service and examines the temporal effects. Paper II investigates the subjective factors influencing a quick-response to the new PT service by proposing a modified attitude-behaviour framework. Paper III and IV analyse the effects of seasonal variations and individuals’ constraints on their day-to-day activity-travel decisions and patterns. Paper V analyses the attrition and fatigue in the two-week travel diary panel survey instrument.

  • 17.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Attrition and Fatigue in a Four Waves of Two-Week Travel Diary: A Case Study in Stockholm, SwedenManuscript (preprint) (Other academic)
    Abstract [en]

    This paper describes a four-wave panel survey design and implementation collected on individual level, consisting of three survey’s instrument namely, self-reported two-week travel diary, on-line psychological questionnaire, and self-reported mental map-related questions. The panel survey is built with the aim to examine individuals’ behavioural changes when a new tram extension line in western sub-urban areas of Stockholm, Sweden, was introduced in October 2013. The survey duration took approximately seven months’ period and the data collected covers all four different seasons of the year, which make it wealth of information. The analysis of attrition and fatigue was done on the two-week travel diary survey instrument only. It is found that the overall attrition rate is 34.3% of the total participants (102 individuals) in the Wave 1 survey, which is considered large. The attrition rate between consecutive waves, however, is considered low which is within the range of 7% to 10%. Based on the binary logit models, there are no systematic tendencies of the dropouts’ characteristics from wave to wave to be found, indicating attrition is purely random. There is no correlation between immobile days and missing trips per day are to be found between-waves. The results of the binary logit model on missing trip show that personal attributes, temporal factors (e.g. weekdays and waves) and travel characteristics (e.g. home-based trip, trip purpose, travel distance and number of inter-modal transfers) significantly affect the missing trip but no indication of fatigue appears.

  • 18.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Subjective Factors Influencing Individual's Response to a New Public Transport ServiceManuscript (preprint) (Other academic)
    Abstract [en]

    The timing and nature of people’s responses can be expected to vary when a new element enter their environment. For example, when an individual is provided with a new or modified transport service. This time-scale of behavioural responses will affect the patronage of, and short- and long-term demands on the new service over time. Understanding the underlying factors that influence an individual’s response over time to a new or modified transport service would enable us to identify trigger factors that make the new service attractive from an individual’s point of view. Chatterjee (2001) and Douglas (2003) argued that motives other than instrumental factors related to public transport use, such as attitudes, awareness, travel habits and learning processes, can influence individual responses over time to changes in the travel environment. Unfortunately, despite their importance, there have been few studies that examined this argument empirically. To address this research gap, this paper aims to investigate the influences of subjective factors on individuals’ responses to the introduction of a modified public transport (PT) service over time by proposing and testing an alternative model that modifies the theory of planned behaviour (TPB) model framework. This paper also aims to investigate the behavioural change in terms of attitudes and perceptions on individuals’ resources and constraints in using a modified PT service over time after its introduction. The case study involves the new extension of a tram line connecting the suburbs of Alvik and Solna Centrum in Stockholm, Sweden. Four waves of a panel survey were conducted with 96 individuals who lived along the new service, from just before the new service was introduced and until seven months after its introduction. A structural equation modelling technique was used to estimate the relationships between behavioural constructs and panel data, then incorporate them into a discrete choice model. The results show that intention influences individual’s quick-response choice. The panel analysis shows that past behaviour in using the new service influenced current behaviour, and that perceived walking distance in using the service consistently influenced the frequency of using the new service over time.

  • 19.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Universiti Tun Hussein Onn Malaysia, Faculty of Civil and Environmental Engineering, Department of Infrastructure and Geomatic Engineering.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Franklin, Joel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Liu, Chengxi
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. VTI.
    Understanding Seasonal Variation in Individual's Activity Participation and Trip Generation by Using Four Consecutive Two-Week Travel DiaryManuscript (preprint) (Other academic)
    Abstract [en]

    This paper explores the interactions between travel demand, time allocation and mode choice in different seasons by jointly modeling the work and/or study, routine and leisure activity-travel engagements of 67 individuals in Stockholm, Sweden. A longitudinal panel two-week travel diary data collected in four consecutive waves over a span of seven months period that covers all four different seasons; autumn, winter, spring and summer, were analysed by using simultaneous Tobit models. The model was applied to explore the interactions among each activity-travel indicator, and individuals’ unique characteristics and endogeneity in activity-travel engagements between different seasons were also considered in the model system. The results of models reveal clear trade-offs between mandatory activities (work and/or study) and non-mandatory activities (routine and leisure), regardless of any seasons, although the magnitudes vary between seasons. There is also a positive mutual endogeneity relationship between number of trips and activity duration within the same activity type. The trade-offs between work and/or study trips towards routine and leisure trips are larger in winter and spring respectively, than in other seasons. It is also found that mode effects on travel time for conducting mandatory activity are much larger in spring than in other seasons. However, the effects of public transport and slow modes on travel time for leisure activities are much larger in summer than in other seasons.

  • 20.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Franklin, Joel P.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Examining the effects of out-of-home and in-home constraints on leisure activity participation in different seasons of the year2016In: Transportation, ISSN 0049-4488, E-ISSN 1572-9435, p. 1-25Article in journal (Refereed)
    Abstract [en]

    Using multi-day, multi-period travel diaries data of 56 days (four waves of two-week diaries) for 67 individuals in Stockholm, this study aims to examine the effects of out-of-home and in-home constraints (e.g. teleworking, studying at home, doing the laundry, cleaning and taking care of other household member[s]) on individuals’ day-to-day leisure activity participation decisions in four different seasons. This study also aims to explore the effects of various types of working schedules (fixed, shift, partial- and full-flexible) on individuals’ decisions to participate in day-to-day leisure activities. A pooled model (56 days) and wave-specific models (14 days in each wave) are estimated by using dynamic ordered Probit models. The effects of various types of working schedules are estimated by using 28 days of two waves’ data. The results show that an individual’s leisure activity participation decision is significantly influenced by out-of-home work durations but not influenced by in-home constraints, regardless of any seasons. Individuals with shift working hours engage less in day-to-day leisure activities than other workers’ types in both spring and summer seasons. The thermal indicator significantly affects individuals’ leisure activity participation decisions during the autumn season. Individuals exhibit routine behaviour characterized by repeated decisions in participating in day-to-day leisure activities that can last up to 14 days, regardless of any seasons.

  • 21.
    Ahmad Termida, Nursitihazlin
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Susilo, Yusak O.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Franklin, Joel P.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Observing dynamic behavioural responses due to the extension of a tram line by using panel survey2016In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 86, p. 78-95Article in journal (Refereed)
    Abstract [en]

    Using a four-wave panel survey of individuals' trips and psychological attributes collected among residents along a new tram line extension in the city of Stockholm, Sweden, this study aims to investigate factors that determine the individuals' learning and decision-making processes in using a new transport option. This includes investigating which group of travellers have used the new tram extension earlier than others, and integrated the tram extension as a part of their daily travel patterns. This paper also describes the design and construction of the four-wave panel data collection, which was collected from two weeks before and up to seven months after the opening of the new option. Descriptive analysis shows that within a seven-month period, 79% of the respondents tried the new tram extension but only 14.9% of them adopted the new option as their daily travel mode. During the observed period, about 49.3% of the respondents migrated between travel modes for non-discretionary trips. Further multivariate analysis shows that middle-income travellers and travellers who owned car(s) used the new tram extension earlier than others. The effect of past experience on the current use of the tram extension on a day-to-day basis was also examined by using a mixed logit model with panel data. The purpose of the model is to examine whether individuals' daily experiences with the new tram extension that result from repeated previous choices would affect their decisions to maintain using the new option in subsequent waves.

  • 22.
    Ahmadi, Parisa
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Analysis of traffic patterns for large scale outdoor events: A case study of Vasaloppet ski event2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Vasaloppet is a cross country ski event which has been held in Sweden for about 50 years. Now

    more than 50,000 people of different ages participate in various cross country ski races during the

    Vasaloppet winter week in Dalarna County. This increasing demand needs good traffic and

    transportation planning to avoid congestion and provide safe, on time and environmentally

    friendly transportation for participants and visitors to the area. The key for a good event traffic

    planning is reliable and up-to-date traffic data which is not available for the Vasaloppet winter

    week.

    This study is an attempt to collect traffic data in order to find the movement patterns in the area

    and estimate origin-destination matrices for the main event of Vasaloppet week. Based on

    resources and time limitation it was decided to use a web-base

    d participants’ survey in order to

    collect traffic data. The link to the survey was sent to email address of a sample of 5000

    participants.

    About 64% of the participants drove from their home town to the area and about 31 percent

    travelled by bus. Train and airplane have a very small share in travel mode to the area. Malungsälen,

    Mora and Älvdalen are three municipalities in Dalarna County with the highest share in

    accommodating participants. On the day of the race, bus and car have approximately the same

    share in travel mode with 45% and 47% respectively.

  • 23.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. Swedish National Road and Transport Research Institute (VTI).
    Biligiri, Krishna Prapoorna
    Department of Civil Engineering Indian Institute of Technology Kharagpur .
    Hakim, Hassan
    Swedish National Road and Transport Research Institute (VTI).
    An Algorithm to Estimate Rational Values of Phase Angles and Moduli of Asphalt Mixtures2013In: International Journal of Pavement Research and Technology, ISSN 1996-6814, Vol. 6, no 6, p. 745-754Article in journal (Refereed)
    Abstract [en]

    The objective of this study was to develop and evaluate an algorithm based on Fast Fourier Transform (FFT) that can calculate rational values of phase angle (f) and moduli of the variants of asphalt mixtures for the data obtained from the different frequency sweep tests. f and moduli for ten different asphalt mixtures resulting in over 690 data points collected from both USA and Sweden were computed using FFT. Theoretical observations revealed that there were significant differences for f between FFT and other methods to the order of 10-50%; however, there was no difference in moduli estimates for any mix and was independent of the test. Precisely, the FFT method produced rational f for mixtures that deviate from conventional mixture properties. Furthermore, statistical comparisons corroborated the predicted f estimates indicative of significant differences between the analysis techniques; but, the moduli were unaffected by the analysis methods. The study successfully illustrated the FFT technique, a user-friendly analytical procedure that can obviate the errors in the rational estimation of the acutely sensitive viscoelastic parameters.

  • 24.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science. Swedish National Road and Transport Research Institute, Sweden.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Transport Science. Swedish National Road and Transport Research Institute, Sweden; University of Iceland.
    Characterisation of heavy traffic axle load spectra for mechanistic-empirical pavement design applications2015In: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268X, Vol. 16, no 6, p. 488-501Article in journal (Refereed)
    Abstract [en]

    Heavy traffic axle load spectrum (ALS) is one of the key inputs for mechanistic-empirical analysis and design of pavement structures. Frequently, the entire ALS is aggregated into number of equivalent single axle loads or assumed to have constant contact area (CCA) or constant contact pressure. These characterisations affect the accuracy and computational performance of the pavement analysis. The objective of this study was to evaluate these characterisations based on predicted performances to rutting and fatigue cracking of several pavement structures subjected to ALS data collected from 12 bridge weigh in motion stations. The results indicated that for layers below the top 25cm, all characterisations produced similar values of predicted rutting. However, for the top 25cm, the methods differed in the predicted performances to rutting and fatigue cracking. Furthermore, an improvement to the CCA approach was proposed that enhanced the accuracy while maintaining the same level of computational performance.

  • 25.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. VTI.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. VTI.
    Characterization of heavy traffic axle load spectra for mechanistic-empirical pavement design applicationsIn: The international journal of pavement engineering, ISSN 1029-8436, E-ISSN 1477-268XArticle in journal (Refereed)
  • 26.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science. Swedish National Road and Transport Research Institute, Sweden.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Transport Science. Swedish National Road and Transport Research Institute, Sweden.
    Evaluation of a permanent deformation model for asphalt concrete mixtures using extra-large wheel tracking and heavy vehicle simulator tests2015In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 16, no 1, p. 154-171Article in journal (Refereed)
    Abstract [en]

    This paper evaluates a mechanistic–empirical permanent strain model for asphalt concrete mixtures. The evaluation was carried out based on two different types of tests: an extra-large wheel-tracking (ELWT) test and a full-scale accelerated pavement test using a heavy vehicle simulator (HVS). Asphalt slabs from three different types of asphalt mixtures were prepared for the ELWT test and tested at several pavement temperatures and tyre inflation pressures. Lateral wandering was also incorporated. The measured permanent deformations in the asphalt slabs were thereafter modelled using the permanent strain model from the US Mechanistic-Empirical Pavement Design Guide and model parameters were estimated for the three types of mixes. For validation, data from an HVS tested pavement structure consisting of the same asphalt mixtures as those tested using the ELWT were used. A set of calibration factors for the three mixtures were therefore obtained between the two tests. In all cases, the calibration factors were within ±20% from unity. Differences in geometry, scale, wheel loading configuration as well as the speed of loading between the two test devices could be the possible reasons for the differences in observed calibration factors.

  • 27.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Erlingsson, Sigurdur
    Evaluation of permanent deformation models for unbound granular materials using accelerated pavement tests2013In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 14, no 1, p. 178-195Article in journal (Refereed)
    Abstract [en]

    Mechanistic-empirical (M-E) pavement design methods have become the focus of modern pavement design procedure. One of the main distresses that M-E design methods attempt to control is permanent deformation (rutting). The objective of this paper is to evaluate three M-E permanent deformation models for unbound granular materials, one from the US M-E pavement design guide and two other relatively new models. Two series of heavy vehicle simulator (HVS) tests with three different types of base material were used for this purpose. The permanent deformation, wheel loading, pavement temperature, and other material properties were continuously controlled during the HVS tests. Asphalt concrete layers were considered as linear elastic where stress-dependent behaviour of unbound materials was considered when computing responses for the M-E permanent deformation models with a nonlinear elastic response model. Traffic wandering was also accounted for in modelling the traffic by assuming it was normally distributed and a time-hardening approach was applied to add together the permanent deformation contributions from different stress levels. The measured and predicted permanent deformations are in general in good agreement with only small discrepancies between the models. Model parameters were also estimated for three different types of material.

  • 28.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. Swedish National Road and Transport Research Institute, Pavement Technology, VTI, Linköping, Sweden .
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Pavement Technology, VTI, Linköping, Sweden .
    Modeling of flexible pavement structure behavior - Comparisons with Heavy Vehicle Simulator measurements2012In: Advances in Pavement Design Through Full-Scale Accelerated Pavement Testing - Proceedings of the 4th International Conference on Accelerated Pavement Testing, 2012, p. 493-503Conference paper (Refereed)
    Abstract [en]

    A response model to be employed in a mechanistic-empirical pavement performance prediction model based on multilayer elastic theory has been developed.An iterative approach using a method of successive over-relaxation of a stress dependency model is used to account for the nonlinear behavior of unbound materials. Asphalt and subgrade materials are assumed to be linear elastic. The response model was verified against two series of Heavy Vehicle Simulator (HVS) response measurements made under a variety of wheel load configurations and at different pavement temperatures.A comparison with FallingWeight Deflectometer (FWD) data was also carried out. The model was subsequently used to predict permanent deformation from the HVS testing using simplework hardening models.Atime hardening approach has been adopted to combine permanent deformation contributions from stress levels of different magnitude.The response model outputs and the predicted permanent deformations were generally in good agreement with the measurements.

  • 29.
    Ahmed, Abubeker W.
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. VTI.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering. VTI.
    Viscoelastic modelling of pavement structure behaviour in a full scale accelerated pavement testManuscript (preprint) (Other academic)
  • 30.
    Ahmed, Abubeker Worake
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Mechanistic-Empirical Modelling of Flexible Pavement Performance: Verifications Using APT Measurements2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Mechanistic-Empirical  (M-E)  pavement  design  procedures  are  composed  of  a  reliable  response model to estimate the state of stress in the pavement and distress models in order to predict the different types of pavement distresses due to the prevailing traffic and environmental conditions. One of the main objectives of this study was to develop a response model based on multilayer elastic  theory   (MLET)  with  improved  computational  performance  by   optimizing  the   time consuming parts of the MLET processes. A comprehensive comparison of the developed program with  two  widely  used  programs  demonstrated  excellent  agreement  and  improved  computational performance.  Moreover,  the  program  was  extended  to  incorporate  the  viscoelastic  behaviour  of bituminous materials through elastic-viscoelastic correspondence principle. A procedure based on collocation of linear viscoelastic (LVE) solutions at selected key time durations was also proposed that improved the computational performance for LVE analysis of stationary and moving loads. A comparison  of  the  LVE  responses  with  measurements  from  accelerated  pavement  testing  (APT) revealed a good agreement. Furthermore the developed response model was employed to evaluate permanent deformation models  for  bound  and  unbound  granular  materials  (UGMs)  using  full  scale  APTs.  The  M-E Pavement  Design  Guide  (MEPDG)  model  for  UGMs  and  two  relatively  new  models  were evaluated  to  model  the  permanent  deformation  in  UGMs.  Moreover,  for  bound  materials,  the simplified  form  of  the  MEPDG  model  for  bituminous  bound  layers  was  also  evaluated.  The measured  and  predicted  permanent  deformations  were  in  general  in  good  agreement,  with  only small discrepancies between the models. Finally, as heavy traffic loading is one of the main factors affecting the performance of flexible pavement, three types of characterizations for heavy traffic axle load spectrum for M-E analysis and design of pavement structures were evaluated. The study recommended an improved approach that enhanced the accuracy and computational performance. 

  • 31.
    Ait Ali, Abderrahman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Lindberg, Per Olov
    KTH.
    Nilsson, Jan-Eric
    Eliasson, Jonas
    Aronsson, Martin
    Disaggregation in Bundle Methods: Application to the Train Timetabling Problem2017Conference paper (Refereed)
    Abstract [en]

    Bundle methods are often used to solve dual problems that arise from Lagrangian relaxations of large scale optimization problems. An example of such problems is the train timetabling problem. This paper focuses on solving a dual problem that arises from Lagrangian relaxation of a train timetabling optimization program. The dual problem is solved using bundle methods. We formulate and compare the performances of two different bundle methods: the aggregate method, which is a standard method, and a new, disaggregate, method which is proposed here. The two methods were tested on realistic train timetabling scenarios from the Iron Ore railway line. The numerical results show that the new disaggregate approach generally yields faster convergence than the standard aggregate approach.

  • 32.
    Ait Ali, Abderrahman
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Warg, Jennifer
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Eliasson, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Measuring the Socio-economic Benefits of Train Timetables: Application to Commuter Train Services in Stockholm2017In: 20th EURO Working Group on Transportation Meeting, EWGT 2017, 4-6 September 2017, Budapest, Hungary, Elsevier, 2017, Vol. 27, p. 849-856Conference paper (Refereed)
    Abstract [en]

    On highly used railway lines with heterogeneous traffic, timetabling is challenging. In particular, the limited existing capacity means that to guarantee an acceptable level of quality, the infrastructure manager must cancel some train services on the expense of others. In this article, we study the conflict between commercial long-distance trains and subsidized commuter trains with a socio-economic perspective (i.e. travelers and train operators). The study attempts to answer the following question: What is the socio-economic effect of modifying the timetable of a commuter service?The case study treats the commuter train services in Stockholm. Trip data was collected from the local commuter train operator. An entropy maximization-based model was implemented to estimate the dynamic network Origin-Destination (OD) matrix. This dynamic matrix, of one full working day, was then used to estimate the number of travelers per train, and further converted for use in the microscopic simulation tool RailSys. Travel and waiting time are estimated for each OD pair and with that the generalized costs for the travelers and operators. The effect of crowding in the trains is included in the estimation. The article can be considered as an initiation to a novel method to calculate effects of changes in commuter train timetables. This novel approach enables to price commercial train slots in the capacity allocation process such as in an auction. It provides a new way to estimate the local train operator´s valuation of the different parameters (i.e. waiting, travel time and interchanges). Using RailSys for the estimation of times makes it possible to include capacity aspects that normally are difficult to reveal.

  • 33. Akulich, A
    et al.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Laboratorieundersökningar av åldringsegenskaper hos dränerande asfaltbetong1992Report (Other academic)
  • 34.
    Alam, Sheikh Ariful
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Evaluation of the potential locations for logistics hubs: A case srudy for a logistics company2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The location of logistics hubs is one of the most crucial success factors for potential economic

    growth in logistics sector. Since the logistics hub has direct and indirect impacts on different

    stakeholders including investors, policy makers, infrastructure providers, hub operators, hub

    users and the community itself, it needs to be considered carefully. Therefore, logistics hubs

    should be located in such a way that it can provide a better accessibility to three different modes

    of transportation- road, rail and waterways. The aim of this study is to evaluate the potential

    locations for logistics hubs and to find out the criteria that affect for the selection of location for

    logistics hubs. A comprehensive literature study reveals the factors that are affecting the

    selection of location for logistics hubs and the methods to evaluate those locations considering

    the criteria. Location selection or evaluation is a typical multi-criteria decision making (MCDM)

    problem in which performance criteria plays a vital role for the final decision making. Both

    qualitative and quantitative MCDM methods are applied in this study, where the Analytic

    Hierarchy Process (AHP) is qualitative and the gravity method is quantitative method. Analytic

    Hierarchy Process (AHP) is a structured approach to reach the final decision which is one of the

    best methods of all MCDM problems, used in recent literature to evaluate the location selection

    problems. A case study is done for the logistics company, Brinova Fastigheter AB in Sweden.

    This study is followed by AHP method which is considered with selected factors, i.e. highway

    accessibility, intermodal capacity, port capacity and land availability. Moreover, this study is

    conducted by evaluating the four major potential locations in Sweden i.e. Stockholm, Göteborg,

    Helsingborg and Karlshamn for selecting as a logistics hub. Besides, the location for selecting

    logistics hubs is evaluated by the gravity method, which is a quantitative method to determine

    the level of accessibility for the selected locations, considering the flow of goods both inbound

    and outbound and the transport cost between the locations. The result from the AHP method

    recommend that Göteborg is the best potential location to establish logistic hub whereas the

    Gravity model represents that Stockholm has the highest level of accessibility for logistics

    activity. Therefore the study suggested that both Göteborg and Stockholm are considered to be

    the best potential locations considering in present situation

  • 35.
    Alemu, Beakal Tadesse
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Collocation of Infrastructuresin Stockholm Airport City: Collocation of infrastructures to foster implementation ofnew transportation systems2010Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 36.
    Algers, Staffan
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Even more possibilities to combine demand models2011Conference paper (Other academic)
  • 37.
    Algers, Staffan
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    New models for high speed rail forecasting2011Conference paper (Other academic)
  • 38.
    Algers, Staffan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Beser Hugosson, Muriel
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Modelling choice of flight and booking class - a study using Stated Preference and Revealed Preference data2001In: International Journal of Services Technology and Management, Vol. 2, no 1/2Article in journal (Refereed)
  • 39.
    Algers, Staffan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Petz, M.
    Embedded parks in Quiet Zones2012In: 41st International Congress and Exposition on Noise Control Engineering 2012, INTER-NOISE 2012: Volume 4, 2012, 2012, p. 3024-3035Conference paper (Refereed)
    Abstract [en]

    One of the targets of the European project "CityHush Acoustically Green Road Vehicles and City Areas" under the 7th Framework Program is to support city administrations to eliminate harmful effects of noise exposure and decrease levels of transport noise, especially in urban areas. A particular attention has been paid to investigating boundary conditions and maximum noise gains especially for parks embedded in Q-zones where only quiet low emission vehicles are tolerated. Other vehicles are banned or subject to a noise fee for entering the quiet zone. Within the CityHush project existing noise levels in different parks of European cities were determined and the influence of local parameters on the noise situation, such as size of a Qzone, was investigated. Moreover a variation of noise fees and traffic restrictions as well as different percentages of low noise vehicle ownerships inside the Q-zone and outside (countrywide) was evaluated. Based on different noise and annoyance criteria possibilities and limits to reduce noise in the city environment will be shown, based on studies carried out for 5 European cities.

  • 40. Allström, A.
    et al.
    Kristoffersson, Ida
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. cVTI Swedish National Road and Transport Research Institute, Sweden.
    Susilo, Yusak
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Smartphone based travel diary collection: Experiences from a field trial in Stockholm2017In: Emerging technologies and models for transport and mobility 44th European Transport Conference Selected Proceedings, Casa Convalescència, Barcelona, Spain, 5-7 October 2016, Elsevier, 2017, Vol. 26, p. 32-38Conference paper (Refereed)
    Abstract [en]

    Currently, there is a great need for new methods to collect travel data. Traditional methods have considerable drawbacks and, at the same time, the models used to analyse the transport system require more and more detailed and high-quality data. An alternative method that stands out as very promising is to capture raw data from devices that can use any positioning technology (e.g., GPS, WiFi positioning, GSM, etc.), followed by transforming the raw data into meaningful travel data. Since most smartphones are equipped with various sensors that can be used to determine the location of the smartphone, and since smartphones are integrated in the daily life of most people, they provide an unprecedented opportunity for large-scale travel data collection. This method has a great potential to solve the problems related to the estimation of distance/travel time, geographic coding of departure/destination locations and forgotten trips and it will also provide a more detailed and extensive data set. In a recently completed research project the feasibility of replacing or complementing the traditional travel diary, with a suite of tools that make use of smartphone collected travel data has been evaluated. The advantages and disadvantages of the traditional method and the proposed method were studied. For a fair comparison, both methods have been tested in the same city, at the same time, and with the same respondents. To achieve the objectives of the project, MEILI, a system that consists of a smartphone application for capturing the movement of users and a web application for allowing the users to annotate their movement, has been deployed. The recruitment of respondents is a critical phase for traditional travel diaries and, as expected, this was the case also for the smartphone based method. A lesson learnt was that it is important to simplify the registration process as much as possible. In total 2142 trips were collected and annotated by 171 users. 51 of the users annotated trips covering more than a week. The experiences from the field trial shows that a smartphone based travel diary collection is a very useful complement to traditional travel diary collection methods since it appeals to a different age group and collects more detailed travel data for a longer period. The main findings of the paper are that smartphone based data collection is feasible, that the algorithms to save battery work well and that trips of the same respondent vary considerably depending on day of the week.

  • 41. Allström, Andreas
    et al.
    Rahmani, Mahmood
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Koutsopoulos, Haris
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Gundlegård, David
    Archer, Jeffery
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Mobile Millennium Stockholm2011In: Proceedings of the 2nd International Conference on Models and Technologies for ITS, 2011Conference paper (Refereed)
  • 42. Almquist, T.
    et al.
    Jacobson, S. H.
    Mobarrez, F.
    Näsman, Per
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Hjemdahl, P.
    Lipid-lowering treatment and inflammatory mediators in diabetes and chronic kidney disease2014In: European Journal of Clinical Investigation, ISSN 0014-2972, E-ISSN 1365-2362, Vol. 44, no 3, p. 276-284Article in journal (Refereed)
    Abstract [en]

    Background: Inflammation may contribute to the high cardiovascular risk in diabetes mellitus (DM) and chronic kidney disease (CKD). Monocyte chemoattractant protein-1 (MCP-1) facilitates the recruitment of monocytes into atherosclerotic lesions and is involved in diabetic nephropathy. Interferon gamma (IFNγ) is important in atherosclerosis and increases the synthesis of chemokines including MCP-1. Lipid-lowering treatment (LLT) with statins may have anti-inflammatory effects, and ezetimibe cotreatment provides additional cholesterol lowering. Methods: After a placebo run-in period, the effects of simvastatin alone (S) or simvastatin + ezetimibe (S+E) were compared in a randomized, double-blind, cross-over study on inflammatory parameters. Eighteen DM patients with estimated glomerular filtration rate (eGFR) 15-59 mL/min × 1·73 m2 (CKD stages 3-4) (DM-CKD) and 21 DM patients with eGFR > 75 mL/min (DM only) were included. Results: At baseline, monocyte chemoattractant protein 1 (MCP-1) (P = 0·03), IFNγ (P = 0·02), tumour necrosis factor-α (TNFα) (P < 0·01) and soluble vascular adhesion molecule (sVCAM) (P = 0·001) levels were elevated in DM-CKD compared with DM-only patients. LLT with S and S+E reduced MCP-1 levels (P < 0·01 by anova) and IFNγ levels (P < 0·01) in DM-CKD patients but not in DM-only patients. Reductions were most pronounced with the combination treatment. Conclusions: DM patients with CKD stages 3-4 had increased inflammatory activity compared with DM patients with normal GFR. Lipid-lowering treatment decreased the levels of MCP-1 and IFNγ in DM patients with concomitant CKD, which may be beneficial with regard to the progression of both atherosclerosis and diabetic nephropathy.

  • 43.
    Almqvist, Ylva
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Nedbrytning av vägar: Jämförelse mellan axlar med singel- respektive tvillingmontage2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    When designing roads it’s important to know

    what loads will be

    driven on it. The axles on heavy vehicles can either have super single tires or

    dual tires which, according to studies, damage the roads differently. The Swedish

    Transport Administration is developing an understanding for the character of

    these different kinds of axle and tire types on the loads induced on Swedish

    roads. In this thesis a field study was conducted to determine the distribution

    between axles with super single tires and axles with dual tires on heavy vehicles.

    A highway, a country road and a national road were investigated during the

    study. The result showed that the number of trucks with single tire axles, i.e.

    those with super single tires, varies between 39 and 48 percent on the different

    types of road. That the truck has a single tire axle means that the truck has at

    least one axle with single tires in addition to the steering axle. A small study was

    conducted to determine the width of tires on heavy vehicles.

    A comparison of trucks with single- and dual tire axles was carried out in

    terms of degradation of the roads. Permanent deformation of unbound layers and

    fatigue cracking were investigated since these degradation mechanisms are

    currently used as design parameters in the design of roads. Load values from

    Bridge Weight In Motion (BWIM) data were used in the calculations and vehicle

    type 113, 123 and 12211 were investigated. Permanent deformation and fatigue

    cracking were calculated according to the criteria given in ATB VÄG 2005.

    Dissipated Creep Strain Energy (DCSE) has been calculated for the selected

    truck types. The study showed that trucks with axles with single tires accelerate

    the degradation of the roads. The permanent deformation was almost the same

    for the two different kinds of axle types.

  • 44. Almroth, Andreas
    et al.
    Berglund, Svante
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Engelsson, Leonid
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Canella, Olivier
    Flötteröd, Gunnar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Kristoffersson, Ida
    West, Jens
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering. SWECO, Sweden.
    Further development of SAMPERS and modeling of urban congestion2014Report (Other academic)
    Abstract [en]

    The need to more precisely represent the consequences of congestion mitigation policies in urban transport systems calls for replacement of the static equilibrium assignment by DTA in the integrated travel demand and traffic assignment models. Despite of the availability of DTA models and despite of the conceptual clarity of how such integration should take place, only few operational model systems have been developed for large-scale applications. We report on replacement of the static traffic assignment by two different DTAs in the four stage demand model for the Greater Stockholm region: the macroscopic analytic Visum DUE and microscopic simulation Transmodeler. First results show that even without systematic calibration the DTA is in reasonable agreement with observed traffic counts and travel times. The presented experiments did not reveal striking difference between using macroscopic and microscopic assignment package. However, given the clear trend to microscopic modeling and simulation on the travel demand side, the use of micro-simulation-based DTA package appears more natural from system integration perspective.

  • 45.
    Almström, Peter
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, System analysis and economics. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Three essays on transport CBA uncertainty2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cost Benefit Analysis (CBA) has for a long time been used in transport planning, but it is often questioned. One main argument against CBA is that the results depend largely on assumptions regarding one or a few input factors, as for example the future fuel price or valuation of CO2 emissions.

    The three papers included in this thesis investigate some aspects of uncertainty in transport CBA calculations. The two first papers explore how changes in input data assumptions affect the CBA ranking of six rail and road investments in Stockholm. The first paper deals with the effect of different land-use assumptions while the second deals with the influence of economic growth, driving cost and public transport fare. The third paper investigates how alternative formulations of the public transport mode choice and route choice affect travel flows, ticket revenues and consumer surplus. These are important factors previously known to affect CBA results.

    The findings of the first two papers suggest that CBA results are robust concerning different land-use scenarios and single input factors. No change in rank between a road and a rail object is observed in the performed model calculations, and only one change between two road objects. The fact that CBA results seem robust regarding input assumptions supports the use CBA as a tool for selecting transport investments. The results in the third paper indicate that if there is detailed interest in, for example, number of boardings and ticket income from a certain transit line, or the total benefit of a price change, a more detailed formulation of the public transport mode choice and route choice will provide more reliable results. On the other hand, this formulation requires substantially more data on the transit line and price structure than the conventional formulation used in Swedish transport planning, especially in areas with many different pricing systems.

  • 46. Almström, Peter
    et al.
    Berglund, Svante
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Börjesson, Maria
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Land use planning and transport investment appraisal2011Conference paper (Refereed)
  • 47. Almström, Peter
    et al.
    Berglund, Svante
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Börjesson, Maria
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis. KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    The impact of land use planning on Cost-Benefit Analysis rankings2011In: Proceedings of the European Transport Conference, 2011Conference paper (Refereed)
  • 48.
    Almström, Peter
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Berglund, Svante
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Börjesson, Maria
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Jonsson, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    The impact of travel costs and economic growth on cost-benefit analysis rankings2012Manuscript (preprint) (Other academic)
    Abstract [en]

    The use of Cost-benefit analysis (CBA) as a tool for selecting transport investments is often questioned. It is not unusual that politicians or others in the public debate argue that the outcome of a CBA completely rely on assumptions concerning a particular input factor, such as valuation of CO2 emissions or future fuel price. This paper explores whether the relative ranking of CBA outcomes are robust with respect to some key inputs in transport demand analysis driving cost, public transport fare and economic growth. We study six different infrastructure objects (three road and three rail objects) and four alternative assumptions on input factors compared to a reference scenario.

    The findings suggest that single input factors in a CBA, individually have a small impact on the ranking of the studied investments. In our model calculations we observe no change in rank between a road and a rail object.

  • 49.
    Almström, Peter
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
    Engelson, Leonid
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    Algers, Staffan
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS. KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport and Location Analysis.
    Modelling the effect of transit supply and price structure on mode choice and route choice2011Conference paper (Refereed)
    Abstract [en]

    This paper develops a new mode choice and transit route choice model for work trips by either car or transit. In contrast to the conventional regional traffic models used for transportation planning in Sweden, the model accounts for the fact that the value of time varies within a population of travellers making a trip with the same purpose and the fact that the price can differ between different transit lines (bus, regional trains, etc.). A mixed binomial logit (MXL) model with a lognormally distributed cost parameter has been estimated for the mode choice. The MXL specification makes it possible to capture some of the variation in the value of time. The transit route choice model rests on the assumption that transit commuters purchase travel passes that are valid for a certain time period, e.g. a month. The travel pass then allows the traveller to use a certain set of transit lines, while others are not available. For the mode choice, the traveller compares travel cost and time with the chosen pass with the travel cost and time by car. The results from performed analyses indicate that if the interest is in overall mode share and overall travel flows, the conventional method in Swedish transport modelling will suffice. However, if the interest is more detailed, for example concerning boardings and ticket income from a certain transit line, or the total benefit of a price change, the model developed in this paper will give more reliable results.

  • 50. Al-Mudhaffar, Azhar
    et al.
    Nissan, Albania
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Bång, Karl-Lennart
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Bus stop and bus terminal capacity2016In: TRANSPORT RESEARCH ARENA TRA2016, Elsevier, 2016, p. 1762-1771Conference paper (Refereed)
    Abstract [en]

    Stockholm is growing fast leading to an increased demand for public transport services and facilities. This has subsequently led to challenges to provide suitable bus terminals. The Municipalities are keen to provide good public transport but have difficulties providing the needed space. There is also a lack of knowledge in this problem area. A comprehensive study is therefore undertaken including literature review, field studies and modeling of the capacity of different types of bus stops and bus terminals. In order to understand and evaluate the capacity of the bus terminals, the starting point is the capacity of loading areas for which there is presently no approved Swedish methodology. A model of capacity based on bus dwell time described by HCM2000 has therefore been used. This model does not consider the bus arrival distribution; therefore it has been applied with a correction factor to better reflect conditions in large cities. Results from performed trials show that this correction factor is reduced at higher dwell time. The calculation of loading areas capacity is the basis for the calculation of bus stop capacity in bus terminals. However, terminal factors such as scheduling and design of the terminals must be taken into account. The procedure for estimating the maximum number of bus departures is also handled in the study. In the long term deeper analysis will be required, e.g. the need for safety zone behind the reversing buses and the demand for dedicated places for layover parking. Socio-economic analyzes of congestion and longer detours because of the increasingly smaller bus terminals should also be raised in these discussions.

1234567 1 - 50 of 1700
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf