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• 1.
KTH, Superseded Departments, Infrastructure and Planning.
On rating of gravel roads2001Doctoral thesis, comprehensive summary (Other scientific)
• 2.
KTH, Superseded Departments, Infrastructure and Planning.
Rating of gravel roads in Sweden2000Licentiate thesis, monograph (Other scientific)
• 3.
KTH, Superseded Departments, Infrastructure and Planning.
Hedonic prices and center accessibility: conceptual foundations and an empirical hedonic study of the market for condominium housing in Singapore1997Doctoral thesis, monograph (Other scientific)

One aim of this study is to compare and evaluateprespecified and data-specific functional forms for theestimation of hedonic price functions. One prespecifiedfunction and three types of data-specific Box-Cox functions areused to estimate hedonic price functions. A second aim of thestudy is to test alternative monocentric and polycentrichypotheses according to a system of successive variablerejections constructed for this study, whereby requiredsignificance levels are influenced by the results of aselection of earlier hedonic price functions.

The possibility of constructing internally consistentcriteria for variable elimination is one of the merits ofemploying a prespecified functional form. Other advantagesinclude the simplicity and transparency of the derived results,and the robustness of key parameter estimates in the face ofmisspecified functions. Using a prespecified form will on theother hand as a rule not yield the likeliest functional form tohave generated the data and cannot be relied on to generatewell-behaved residuals.

Being assured of well-behaved residuals - as is the casewith data-specific Box-Cox functions - is advantageous, eventhough it makes the detection of potential heteroskedasticitymore difficult. Box-Cox models with more than onetransformation parameter are however especially prone to yielddescriptions of unique data sets at the expense of potentialreplicability. Because of the sensitivity of the t-values ofthe estimated independent variables to the estimated Box-Coxt:ransformation parameters - where the log-likelihood partlydepends on the set of independent variables - it becomesdifficult to avoid an arbitrary selection of independentvariables. This is true of all Box-Cox functions, althoughespecially of functions that estimate more than onetransformation parameter.

Although regression results provide detailed information onvariable effects, much of that information is not generalizableowing to interspatial and intertemporal instability. Because ofsupply and demand fluctuations and specification problems, itis argued that is preferable to draw qualitative rather thanquantitative conclusions.

An analysis of the Singapore condominium market illustratesthe conceptual discussion of various approaches to hypothesistesting, with an emphasis on testing hypotheses concerning thenumber and nature of urban centers. The data strongly supportthe realism of the monocentric model with one dominantemployment center. Alternative polycentric and service-centerhypotheses are unambiguously rejected. The signs, averageimplicit prices and t-values of the independent variables arerelatively robust over the range of estimated functional forms- whether pre-specified or Box-Cox - given the set of variablesto be included in the hedonic price equation.

Keywords:Hedonic prices, Box-Cox function, monocentric,polycentric, accessibility, hypothesis testing, rejection ofvariables, data-specific function, prespecified function.

• 4.
KTH, Superseded Departments, Infrastructure and Planning.
Queensland University of Technology. Queensland University of Technology. Queensland University of Technology.
Collection and Use of Railway Track Performance and Maintenance Data2004In: New Horizons for Rail: Proceedings of CORE (Conference On Railway Engineering) 2004, 2004Conference paper (Refereed)

There is increasing pressure for track managers to optimise the mix of infrastructure maintenance and renewal activities so that better performance can be extracted from the asset at lower operating costs. Track related data is usually collected for several purposes with different players (eg: track owners, rail operators and regulators and funding agencies) requiring data at different levels of detail and about different matters. The paper reports on a review of data collection procedures as part of a project funded by the Rail CRC, aimed at "Enhancing the Optimisation of Maintenance/Renewal." The paper also reports on preliminary outcomes of an international survey of current practice with respect to track related data collection and use.

• 5. Berdica, K.
KTH, Superseded Departments, Infrastructure and Planning.
Regional accessibility analysis from a vulnerability perspective2004In: Proceedings of The Second International Symposium on Transportation Network Reliability, INSTR , 2004Conference paper (Other academic)
• 6.
KTH, Superseded Departments, Infrastructure and Planning.
Analysing vulnerability in the road transportation system: putting theory into practice using Sweden as an example2000Licentiate thesis, comprehensive summary (Other scientific)
• 7.
KTH, Superseded Departments, Infrastructure and Planning.
Analysing transportation patterns in cross-border contexts1998Licentiate thesis, monograph (Other scientific)
• 8.
KTH, Superseded Departments, Infrastructure and Planning.
GIS in Transport Modelling2001Doctoral thesis, comprehensive summary (Other scientific)
• 9.
KTH, Superseded Departments, Infrastructure.
KTH, Superseded Departments, Infrastructure and Planning.
Identifying local spatial association in flow data1999In: Journal of Geographical Systems, ISSN 1435-5930, E-ISSN 1435-5949, Vol. 1, no 3, p. 219-236Article in journal (Refereed)

In this paper we develop a spatial association statistic for flow data by generalizing the statistic of Getis-Ord, Gi (and Gi*). This local measure of spatial association, Gij, is associated with each origin-destination pair. We define spatial weight matrices with different metrics in flow space. These spatial weight matrices focus on different aspects of local spatial association. We also define measures which control for generation or attraction nonstationarity. The measures are implemented to examine the spatial association of residuals from two different models. Using the permutation approach, significance bounds are computed for each statistic. In contrast to the Gi statistic, the normal approximation is often appropriate, but the statistics are still correlated. Small sample properties are also briefly discussed.

• 10.
KTH, Superseded Departments, Infrastructure and Planning.
Winter maintenance service levels on cycleways2000Licentiate thesis, monograph (Other scientific)
• 11.
KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Royal Institute of Technology.
KTH, Superseded Departments (pre-2005), Infrastructure and Planning.
A joint between-day and within-day activity based travel demand with forward looking individualsManuscript (preprint) (Other academic)

Including day-to-day planning to account for systematic variability in activity participation has the potential to further improve travel demand models. This paper introduce a dynamic discrete choice model of day-to-day and within-day planning in a joint framework. No model up to date jointly treats within-day and day-to-day planning with individuals that take future days into account. The model is estimated using a combination of a small survey with week long data and a larger single day travel survey. A static, myopic and forward looking version of the model is estimated. There is a big improvement in model fit when moving from a static to a dynamic model, but allowing forward-looking behaviour gives a relatively small additional improvement. As a policy test, grocery stores are closed on Sundays. The myopic model predicts that people as a consequence will shop more on Mondays-Thursdays and therefore unintuitively also less on Saturdays. The forward looking model also predicts increased shopping on weekdays but mainly that people will shop more on Saturdays anticipating that stores are closed on Sundays.

• 12.
KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics. Royal Institute of Technology.
KTH, Superseded Departments (pre-2005), Infrastructure and Planning. KTH, School of Architecture and the Built Environment (ABE), Transport Science, System Analysis and Economics.
Discount factors greater than or equal to one in infinite horizon dynamic discrete choice modelsManuscript (preprint) (Other academic)

In this paper, the theory on infinite horizon DDCM's is extended to allow for discount factors greater than or equal to one. The proposed methods are applied to Rust's (1987) bus engine replacement model, where a discount factor of 1.075 is identified using grid search. The infinite horizon problem with and without a terminal state are treated separately. Sufficient conditions are given for the existence of solutions to Bellman's equation in the terminal state problem and to a normalized version of Bellman's equation in the non-terminal state setting. If a terminal state exists, acting according to Bellman's equation still yields the maximum expected total utility under derived conditions on the one-stage utility functions and reachability of the terminal state. In the non-terminal state problem, $\beta=1$ implies that individuals maximize the average cost per stage, but for $\beta>1$ no rationale for acting according to Bellman's equation, even when it has a solution, has been found.

• 13.
KTH, Superseded Departments, Infrastructure and Planning.
Evaluation and decision-making in the planning process: an analysis based on experiences from Nacka municipality, Sweden1997Licentiate thesis, monograph (Other scientific)
• 14.
KTH, Superseded Departments, Infrastructure and Planning.
Railway, safety and economics1999Licentiate thesis, comprehensive summary (Other scientific)
• 15.
KTH, Superseded Departments, Infrastructure and Planning.
Aspekter på storstadens rumsliga funktionsuppdelning1997Licentiate thesis, monograph (Other scientific)
• 16.
KTH, Superseded Departments, Infrastructure and Planning.
Crime in border regions: The Scandinavian case of Öresund, 1998-20012004In: Annals of the Association of American Geographers, ISSN 0004-5608, E-ISSN 1467-8306, Vol. 94, no 4, p. 807-826Article in journal (Refereed)

This article compares offense patterns at two points in time in Öresund, a Scandinavian border region that spans Sweden and Denmark. The aim of the analysis is to contribute to a better understanding of the relationships between crime and demographic, socioeconomic, and land use covariates in a border area that has been targeted with long-term investments in transport. The changes effected by the construction of the Öresund bridge might be expected to have an impact on both the levels and the geographies of different offenses by creating new sites for offending and new, more vulnerable, transient groups. The article focuses on identifying and explaining changes in the geography of crime before and after the bridge was built. Spatial statistical techniques and GIS underpin the methodology employed. The article shows that there have been changes in the levels and the geography of some offenses. Crime in border regions is likely to be of growing interest in Europe as a result of European Union (EU) enlargement and increasing intra-European cross-border movement facilitated by improved communication systems.

• 17.
KTH, Superseded Departments, Infrastructure and Planning.
Exploring offence statistics in Stockholm City using spatial analysis tools2002In: Annals of the Association of American Geographers, ISSN 0004-5608, E-ISSN 1467-8306, Vol. 92, no 1, p. 29-51Article in journal (Refereed)

The objective of this article is to investigate changes since the early 1980s in offence patterns for residential burglary, theft of and from cars, and vandalism in Stockholm City using methods from spatial statistics. The findings of previous Swedish studies on crime patterns and the insights provided by different theories, notably one propounded by Wikstrom (1991), provide a background for this study and are briefly reviewed. The analytical elements of the article are presented in two main parts. The first consists of a brief description of methodological procedures to obtain robust estimates of small-area standardized offence ratios. Attention is pail to both the spatial framework and the method of calculating rates. Standardized offence ratios (SORs) are calculated and mapped using GIS, and the Getis-Ord statistic is used to identify areas of raised incidence. The variation in a relative risk is modeled as a function of socioeconomic variables using the linear regression model, recognizing the complications raised by the spatial nature of the data. Results suggest that while there have been no dramatic changes in the geographies of these offences in Stockholm City during the last decade, there have been some shifts both in geographical patterns and in their association with underlying socioeconomic conditions.

• 18.
KTH, Superseded Departments, Infrastructure and Planning.
KTH, Superseded Departments, Infrastructure and Planning.
A new information theoretical measure of global and local spatial association, S2002In: The Review of Regional Research, Vol. 22, p. 13-40Article in journal (Refereed)

In this paper a new measure of spatial association, the S statistics, is developed.The proposed measure is based on information theory by defininga spatially weighted information measure (entropy measure) that takes thespatial configuration into account. The proposed S-statistics has an intuitiveinterpretation, and furthermore fulfils properties that are expected from anentropy measure. Moreover, the S statistics is a global measure of spatialassociation that can be decomposed into Local Indicators of Spatial Association(LISA). This new measure is tested using a dataset of employmentin the culture sector that was attached to the wards over Stockholm Countyand later compared with the results from current global and local measuresof spatial association. It is shown that the proposed S statistics share manyproperties with Moran’s I and Getis-Ord Gi statistics. The local Si statisticsshowed significant spatial association similar to the Gi statistic, but has the advantage of being possible to aggregate to a global measure of spatialassociation. The statistics can also be extended to bivariate distributions.It is shown that the commonly used Bayesian empirical approach can beinterpreted as a Kullback-Leibler divergence measure. An advantage of Sstatisticsis that this measure select only the most robust clusters, eliminatingthe contribution of smaller ones composed by few observations and that mayinflate the global measure.

• 19.
KTH, Superseded Departments, Infrastructure and Planning.
Adapting GIS technology to the needs of local planning2000In: Environment and Planning, B: Planning and Design, ISSN 0265-8135, E-ISSN 1472-3417, Vol. 27, no 6, p. 923-937Article in journal (Refereed)

Our objective in this paper is to argue for a new use of geographic information systems-GIS in local planning as an auxiliary tool for decisionmaking. We review the use of the GIS technique in earlier research studies and represent the empirical findings from using GIS in a quality-of-life study in conjunction with an urban renewal project of a residential area in Stockholm County, Sweden. Special attention is given to the potential of GIS for mapping qualitative data representing people's needs and judgments about their residential areas. We conclude with a discussion of future challenges in using GIS techniques in combination with the Internet for social analysis in renewal planning. One of the arguments proposed is that the tool can be used to promote the involvement of urban residents.

• 20.
KTH, Superseded Departments, Infrastructure and Planning.
UNDERSTANDING URBAN PATTERNS Qualitative and Quantitative Approaches2001Doctoral thesis, comprehensive summary (Other scientific)

In this thesis, the main field of study is urban patternsand the methodological issues involving the analysis of spatialdata across urban space. Four particular aspects are chosen toillustrate the dynamics of urban space, using Stockholm Countyas case study. The first aspect deals with residential qualityby comparing three case study areas through use of amultiple-method approach. The second deals with urban areas astargets of planning actions or arenas of citizen participation.Urban areas as risky environments are assessed by looking atchanges in crime patterns since the 1980's, using spatialstatistical measures and Geographic Information Systems (GIS),which in itself constitutes the third chosen aspect underreview. The fourth and final aspect exemplifies the city as aplace of production through the analysis of clusters ofemployment within the culture sector.

Paper I (Ceccato, 1998) deals with the assessment ofresidential quality of life in three case study areas inStockholm County and constitutes the Licentiate thesis.

Paper II (Ceccato&Snickars, 2000) argues for a new useof Geographic Information Systems-GIS in local planning as anauxiliary tool for decision-making.

Paper III (Ceccato et al., 2001) investigates changes sincethe early 1980's in offence patterns for residential burglary,theft of and from cars, and vandalism in Stockholm City usingmethods from spatial statistics.

Paper IV (Ceccato&Karlström, 2000) proposes a newmeasure of spatial association, the S-statistic, which istested using a data set of employment in the cultural sectoracross the Stockholm County.

• 21. Clift, R.
KTH, Superseded Departments, Infrastructure and Planning.
The application of Life Cycle Assessment to Integrated Solid Waste Management - Part 1 - Methodology2000In: Process Safety and Environmental Protection, ISSN 0957-5820, E-ISSN 1744-3598, Vol. 78, no B4, p. 279-287Article in journal (Refereed)

Integrated Waste Management is one of the holistic approaches to environmental and resource management which are emerging from applying the concept of sustainable development. Assessment of waste management options requires application of Life Cycle Assessment (LCA). This paper summarizes the methodology for applying LCA to Integrated Waste Management of Municipal Solid Waste (MSW) developed for and now used by the UK Environment Agency, including recent developments in international fora. Particular attention is devoted to system definition leading to rational and clear compilation of the Life Cycle Inventory, with appropriate 'credit' for recovering materials and/or energy from the waste. LCA of waste management is best seen as a way of structuring information to help decision processes.

• 22.
KTH, Superseded Departments, Infrastructure and Planning.
On the communication of professional environmental perspectives in land-use planning2001Licentiate thesis, comprehensive summary (Other scientific)
• 23.
KTH, Superseded Departments, Infrastructure and Planning.
Creep of prestressed sulphur concrete1996In: Proceedings of the 7th International Conference on Durability of Building Materials and Components, 7DBMC, Stockholm, 1996Conference paper (Refereed)
• 24. Ekvall, T.
KTH, Superseded Departments, Infrastructure and Planning.
The application of life cycle assessment to integrated solid waste management. Part 2 - Perspectives on energy and material recovery from paper2000In: Process Safety and Environmental Protection, ISSN 0957-5820, E-ISSN 1744-3598, Vol. 78, no B4, p. 288-294Article in journal (Refereed)

The environmental aspects of different waste management options for paper materials are the subject of an ongoing debate. A large number of life cycle assessments have been performed in order to study the topic. The comparison between recycling and incineration with energy recovery is often in focus. Different studies have arrived at different conclusions due to differences in the methods applied and assumptions made in the Life cycle inventory analysis (LCI). Key factors for the LCI results include what energy is replaced by incinerated waste paper, what material is replaced by recycled fibres, how the pulpwood savings are used, what external energy carrier is used for the recycling process, and what environmental burdens are associated with a change in the electricity demand. These factors can be investigated for different decision contexts and from different ethical, time and geographical perspectives. Different choices are appropriate for different decisions and perspectives. Hence, to obtain an adequate conclusion, the comparison needs to be specified in terms of what perspectives are relevant.

• 25.
KTH, Superseded Departments, Infrastructure and Planning.
Integrated travel pattern modeling: Theory and estimation of an integrated land use transportation modelArticle in journal (Other academic)
• 26.
KTH, Superseded Departments, Infrastructure and Planning.
Road pricing with limited information and heterogeneous users: A successful case2001In: The annals of regional science, ISSN 0570-1864, E-ISSN 1432-0592, Vol. 35, no 4, p. 595-604Article in journal (Refereed)

Since strictly optimal (first-best) road pricing policies require information that we will probably never have, it is important to investigate what can be done under more restrictive assumptions as to what information is available. One such case is examined in this paper, where the main restrictive assumptions are that all users have the same choice set and that all alternatives have the same monetary cost. Individuals have utility functions with constant marginal utilities of time and money, but these marginal utilities vary across individuals, and are assumed to be unobservable. We show that for this model, any toll reform that reduces aggregate travel time and redistributes the toll revenues equally to all users makes everyone better off. This holds regardless of the distribution of marginal utilities of time and money, and for any road network.

• 27.
KTH, Superseded Departments, Infrastructure and Planning.
The influence of accessibility on residential location: theory and estimation of an integrated land use transportation modelArticle in journal (Other academic)
• 28.
KTH, Superseded Departments, Infrastructure and Planning.
The use of average values of time in road pricing: A note on common misconception2000Doctoral thesis, comprehensive summary (Other academic)
• 29.
KTH, Superseded Departments, Infrastructure and Planning.
Time and income constraints in discrete choice models with an application to mode choice2000Doctoral thesis, comprehensive summary (Other academic)
• 30.
KTH, Superseded Departments, Infrastructure and Planning.
Transport and location analysis2000Doctoral thesis, comprehensive summary (Other scientific)

This dissertation consists of seven papers. InTime and income constraints in discrete choice models withan application to mode choice, we discuss how variouseffects of time and income constraints can be included indiscrete choice models. Several cases of indirect utilityfunctions are estimated and compared, showing that the obtainedvalues of time and elasticities can be very sensitive to modelspecification.

Three papers deal with the development of TILT, Tool forIntegrated analysis of Location and Transport, an integratedland use-transportation model for Stockholm. In the first,The influence of accessibility on residential location,we develop a theoretical framework for modeling thesimultaneous choice of location and travel pattern, showing howthe joint choice of location and average travel pattern can bemodeled. With focus on the location choice, we presentmethodology and results for an estimation of the framework. Inthe second,Integrated travel pattern modeling, the choice of travelpattern in is explained in detail, and estimation methodologyand results are presented.

In the third,A model for integrated analysis of household location andtravel choices(co-authored with Lars-Göran Mattsson),a different derivation of the framework is presented, with amore rigorous treatment of the stochasticity in the travelpattern. Using numerical simulation, we investigate theresulting travel demand functions.

InLocation and transport effects of road pricing - asimulation approach(co-authored with Lars-GöranMattsson), we develop a model of a generic city, usingparameter values from models estimated on real data of locationand travel. The model is used to investigate the effects ontransport and location of a road pricing reform and of a tollring around the city center.

Two papers deal with road pricing in the presence ofunobserved heterogeneity in user preferences. In the first,Road pricing with limited information and heterogeneoususers: a successful case, we show that if all users havethe same choice set and all alternatives have the same monetarycost, any toll reform that reduces aggregate travel time andredistributes the toll revenues equally to all users makeseveryone better off. In the second,The use of average values of time in road pricing - a noteon a common misconception, it is argued that the difficultyto convert time delays into monetary fees when users areheterogeneous has been underestimated or neglected, and thatthere is a common misconception that it is possible to use anaggregate time value for this conversion.

• 31.
KTH, Superseded Departments, Infrastructure and Planning.
KTH, Superseded Departments, Infrastructure and Planning.
Transport and Location Effects of Road Pricing: A Simulation Approach2001In: Journal of Transport Economics and Policy, ISSN 0022-5258, E-ISSN 1754-5951, Vol. 35, no 3, p. 417-456Article in journal (Refereed)

The effects of road pricing on transport and location patterns have been much discussed. However, it is unclear how large the effects are, and whether relocation of households, workplaces and shops will counteract or amplify the effects on transport. In this paper a model of a generic symmetric city is developed. The model is used to investigate the effects of road pricing in the form of congestion pricing and a toll ring. The results indicate that the impacts on location are small compared to the impacts on traffic volumes, modal split, and trip distances. The different effects of congestion pricing and toll rings at different positions are considered.

• 32.
KTH, Superseded Departments, Infrastructure and Planning.
KTH, Superseded Departments, Infrastructure and Planning.
A model for integrated analysis of household location and travel choices2000In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 34, no 5, p. 375-394Article in journal (Refereed)

We develop a model for integrated analysis of household location and travel choices and investigate it from a theoretical point of view. Each household makes a joint choice of location (zone and house type) and a travel pattern that maximizes utility subject to budget and time constraints. Prices for housing are calculated so that demand equals supply in each submarket. The travel pattern consists of a set of expected trip frequencies to different destinations with different modes. The joint time and budget constraints ensure that time and cost sensitivities are consistent throughout the model. Choosing the entire travel pattern at once, as opposed to treating travel decisions as a series of isolated choices, allows the marginal utilities of trips to depend on which other trips are made. When choosing trip frequencies to destinations, households are assumed to prefer variation to an extent varying with the purpose of the trip. The travel pattern will tend to be more evenly distributed across trip ends the less similar destinations and individual preferences are. These heterogeneities of destinations and individual preferences, respectively, are expressed in terms of a set of parameters to be estimated.

• 33. Gudmundsson, Henrik
KTH, Superseded Departments, Infrastructure and Planning.
Sustainable development principles and their implications for transport1996In: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 19, no 3, p. 269-282Article in journal (Refereed)

'Sustainable mobility' has been adopted as an overall objective for European transport policy, and similar intentions are expressed in other parts of the world. However, little has been done to define what 'sustainable mobility' would actually imply for our understanding and assessment of transport. We suspect that this much used term could merely end up acting as a lubricant to the very development it was meant to challenge: The ever increasing movement of people and goods. In this article we attempt to place transport in the context of sustainable development principles. We emphasise the need to include principles of development (increasing well-being and equity) as well as sustainability (preserving natural and man-made capital). Four such principles are suggested, taking inspiration from Herman Daly and others. We then turn to explore the main features of transport, establishing a comprehensive transport concept. The concept combines a systems perspective with a service perspective. Omitting either one would disable a complete consideration of sustainable development. Our confrontation of the four principles with the reality of current transport trends gives rise to several critical implications. The most important of which relate to the contribution of transport to depleting natural capital and quality of life. Moreover, we are also forced to challenge the value of increasing mobility itself, if other forms of access may provide relevant substitutes. The article thereby outlines some conceptual foundations for a transport policy that could qualify as sustainable.

• 34.
KTH, Superseded Departments, Infrastructure and Planning.
Accessibility, generation and license holding effects in car ownership models1998Licentiate thesis, monograph (Other scientific)
• 35.
KTH, Superseded Departments, Infrastructure and Planning.
Analyzing car ownership and route choices using discrete choice models2001Doctoral thesis, monograph (Other scientific)

This thesis consists of two parts. The first part analyzesthe accessibility, generation and license holding effects incar ownership models. The second part develops a route choicemodeling framework with an attempt to address the differencesin drivers' route choice behavior. These two parts of work areboth based on the discrete choice theory - the car ownershipmodels are built up on the standard logit model, whereas theroute choice models are formulated in a mixed logit form.

The study result of the first part shows that measuring theaccessibility by the monetary inclusive value reasonably wellcaptures the mechanism of the accessibility impact. Otheraccessibility proxies such as the parking costs, parking typeand house type are correlated with the accessibility but not toa great extent. Both young and old households are less likelyto have a car. The reduction of the propensity to own a car issignificant for households with average birth year before 1920,whereas this reduction is moderate for households with birthyear between 1920 and 1945. It is also demonstrated thatdriving license holding choice is conditional on the carownership level choice, and that these two choices need to bemodeled in a dynamic framework.

The second part of the work investigates the performance ofthe mixed logit model using both simulated data and empiricalroute switching data. The empirical study mainly focused on theimpacts of information and incident related factors on drivers'route switching behavior.

The result shows that using mixed logit gives a significantimprovement in model performance as well as a more sensitiveexplanation of drivers' decision-making behavior. For apopulation with greatly varying tastes, simply using thestandard logit model to analyze its behavior can yield veryunrealistic results. However, care must be taken when settingthe number of random draws for simulating the choiceprobability of the mixed logit model in order to get reliableestimates.

The empirical results demonstrate that incident relatedfactors such as delay and information reliability havesignificant impacts on drivers' route switching, where themagnitude of the response to the change in the delay is shownto vary significantly between individuals. Other factors, suchas confidence in the estimated delay, gender, frequency of cardriving and attitude towards congestion, also make majorcontributions. In addition, it is found that individual's routeswitching behavior may differ depending on the purpose of thetrip and when the choice is made, i.e. pre-trip oren-route.

Keywords: car ownership, accessibility, logit model,route choice, heterogeneity, mixed logit model

• 36.
KTH, Superseded Departments, Infrastructure and Planning.
KTH, Superseded Departments, Infrastructure.
Fuel cells in a medium-sized city in the year 20202004In: URBAN TRANSPORT X: URBAN TRANSPORT AND THE ENVIRONMENT IN THE 21ST CENTURY / [ed] Wadhwa, LC, 2004, Vol. 16, p. 593-605Conference paper (Refereed)

History of technology tells us that new technologies not only replace older ones, but that quite new patterns of possibilities may also arise. Fuel cell technology is developing fast and many new concepts for the use of fuel cells must be proposed and analysed, since we are facing enormous challenges when defending liveability and quality of life within available resources. The aim of the present article is to describe a vision of how fuel cell technology used in all the municipal vehicles serving a middle-sized urban center might bring us closer to both urban quality and help to fulfil our commitments regarding the climate. This paper is part I of a double-paper, where part II (named "Preliminary assessment of a fuel cell public transport system for a medium sized city in the year 2020") [1] is presented at the same WIT-conference in Dresden (May, 2004). The basic functions of this new public transport system are presented in part I (this paper), with particular focus on those functional qualities figured in the assessment in part-II. The climatic goal for a medium sized city in the year 2020 (in this case: 30 percent less CO2-emissions compared to the level of 1990) may be reached if at least one quarter of the vehicle fleet consists of fuel cell cars or if an advanced system of fuel cell-driven local public transport is installed. A combination would be the very best alternative to prepare the city to face the even tougher climatic goals to come. The city may also substitute its part of the national nuclear power program: if about half of the fuel cell car fleet mentioned above is generating electricity about half of the time the cars are parked. The precondition for local sustainability in this respect is that the initially waste- and bio-based hydrogen production is succeeded by renewable hydrogen production methods, working together. New built up areas may be climatically customised (heated, air conditioned etc.) by heat left over from parked fuel cell cars - while generating electricity - if these buildings are well designed for energy economising and adapted synergy.

• 37.
KTH, Superseded Departments, Infrastructure and Planning.
Environmental issues and debate: Interview with Tuija Hilding Rydevik2004In: Urbanistica, ISSN 0042-1022, no 124, p. 81-82Article, review/survey (Other academic)
• 38.
KTH, Superseded Departments, Infrastructure and Planning.
The strive for sustainability: The perspective of professions and professionals in local environmental work2001Licentiate thesis, monograph (Other scientific)
• 39.
KTH, Superseded Departments, Infrastructure and Planning.
Parking, energy consumption and air pollution2004In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 334, p. 39-45Article in journal (Refereed)

This paper examines the impacts of different ways of parking on environmental effects, mainly vehicle emissions and air pollution. Vehicle energy consumption and the urban air quality at street level, related to location and design of parking establishments, need to be assessed and quantified. In addition, the indoor parking environment needs attention. This paper gives a description of a methodological approach when comparing different parking establishments. The paper also briefly describes a Swedish attempt to create methods and models for assessing and quantifying such problem. The models are the macrolevel model BRAHE, for regional traffic exhaust emission, and the micromodel SimPark, a parking search model attempt combined with emission models. Until now, very limited knowledge exists regarding the various aspects of vehicle parking and environmental effects in the technical field as well as in the social and human behaviour aspects. This requires an interdisciplinary approach to this challenging area for research, development and more directly practically implemented surveys and field studies. In order to illustrate the new evaluation methodology, the paper also contains some results from a pilot study in Stockholm. Given certain assumptions, a study of vehicle emissions from parking in an underground garage compared with kerbside parking has given an emission reduction of about 40% in favour of the parking garage. This study has been done using the models mentioned above.

• 40.
KTH, Superseded Departments, Infrastructure and Planning.
A hundred nodes in the Stockholm region: a simple calculation of the effects on commuting2002In: Environment and Planning, B: Planning and Design, ISSN 0265-8135, E-ISSN 1472-3417, Vol. 29, no 2, p. 197-217Article in journal (Refereed)

The aim of this paper is to provide input to a discussion on the potential for reduced commuting with retained accessibility to work, when the development of information technology sets new conditions, and provides new opportunities, for the location of workplaces. The potential impacts on commuting of a node-structured Stockholm region is calculated. The result of the calculation is presented as a comparison between the node-structured city and a reference scenario for the year 2010. The reference scenario has been designed by the planning authorities in the region. The calculation started with the selection of a number of nodes. The exact number of nodes was not defined in advance. Rather it was a result of requirements for reasonable public transport and on reasonable population densities. This resulted in approximately 100 nodes. These were then treated as attractors of workplaces in the calculation. Some of the commuting trips in the reference scenario were rerouted according to specified assumptions. One assumption was that the desire to cut a trip would increase with distance. Another was that the desire to start working in a node would increase with decreasing distance to the node. A third assumption was that the propensity to work from home would increase with the distance to the workplace in the reference scenario. The calculation resulted in a scenario with considerably shorter commuting trips, with a consequent reduction in commuting volumes, and a subsequent increase in walking and cycling, compared with the reference scenario.

• 41.
KTH, Superseded Departments, Infrastructure and Planning.
Telecommunicators in the multinuclear city2000In: Reshaping Regional Planning / [ed] F. Snickars, B. Olerup & L.-O. Persson, Aldershot: Ashgate, 2000, p. 347-362Chapter in book (Refereed)
• 42.
KTH, Superseded Departments, Infrastructure and Planning.
Telematics in Urban Transport: a DelphiStudy Using Scenarios1997Report (Other academic)
• 43.
KTH, Superseded Departments, Infrastructure and Planning.
Transport telematics in urban systems: A backcasting Delphi study1998In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 3, no 6, p. 445-463Article in journal (Refereed)

This paper includes a presentation of the results from a scenario study on transport telematics in urban passenger transport. An international Delphi panel of 100 experts from 20 countries replied to questions on the feasibility and impact of a restricted number of different technical scenarios. The results show that most experts see substantial potential for limiting certain transport problems if there is broad implementation of transport telematics as described in this study. The majority of experts favoured a scenario based on extended public transport information. In that scenario, environmental gains were in practice paid for in terms of less comfortable trips and longer travel times.

• 44.
KTH, Superseded Departments, Infrastructure and Planning.
Urban transport, information technology and sustainable development.1996In: World Transport Policy & Practice, ISSN 1352-7614, E-ISSN 2040-2929, Vol. 2, no 1-2, p. 46-51Article in journal (Refereed)
• 45.
KTH, Superseded Departments, Infrastructure and Planning.
What is the Point of IT?: Backcasting urban transport and land-use futures2000Doctoral thesis, comprehensive summary (Other scientific)

Sustainable development, future studies, informationtechnology, urban land-use and passenger transport. These arethe five concepts upon which this thesis and the eight papersit contains are based. The thesis includes both a developmentof future studies methodology, especially with regard tobackcasting, and analyses of the relationship betweensustainable development, information technology, transport andland-use in future cities

Paper I (Gudmundsson&Höjer, 1996) suggests foursustainable development principles and discusses theimplications of these four principles for the transportsystem.

Paper II (Höjer&Mattsson, 2000) is amethodological paper where backcasting is discussed in relationto some other future studies approaches. Moreover, the use of anumber of common empirical approaches in such studies iscriticised for being too deterministic.

Paper III (Höjer, 1997) presents a study where fourtechnical scenarios of intelligent transport systems weregenerated and evaluated. The evaluation used a Delphi-inspiredbackcasting approach, where a total of some 100 internationalexperts contributed to a two-round survey.

Paper IV (Höjer, 1998a) highlights three of thescenarios generated in Paper III and elaborates some resultsfrom the evaluation of them.

Paper V (Steen et al., 1999) uses assumptions, based onother studies, regarding global future energy supply as well ason the development of vehicle technology and traffic volumes.Based on these, a scenario of a sustainable transport systemfor Sweden in 2040 is developed.

Paper VI (Höjer, 2000b) looks at how the patterns ofcommuting and land-use can change with new organisationalforms. The change can either contribute to reduced trafficvolumes and a more sustainable transport system, or it can leadsociety even further into unsustainability.

Paper VII (Höjer, 2000a) reports from a calculation ofpotential effects on commuting from a change towards anode-structured Stockholm region. The calculation is based onorigin-destination matrices generated from a traffic analysismodel.

Paper VIII (Höjer, 1996) is a generalising analyticalpaper on the relationship between information technology,especially transport telematics, and sustainabledevelopment.

• 46.
KTH, Superseded Departments, Infrastructure and Planning.
KTH, Superseded Departments, Infrastructure and Planning.
Determinism and backcasting in future studies2000In: Futures: The journal of policy, planning and futures studies, ISSN 0016-3287, E-ISSN 1873-6378, Vol. 32, no 7, p. 613-634Article in journal (Refereed)

In this paper, four frequently cited approaches to future studies are criticised. We use examples mainly from the field of transport research. The first approach is the tendency to try to establish cyclic behaviour in socio-technical changes. The second is the view that transport and communication are positively correlated. The third is the so-called 'hypothesis of constant travel time', according to which, the average daily travel time of a population is more or less stable. The fourth is the alleged causal relationship between urban density and petrol use. The use of these approaches is criticised for a number of reasons, among others for over-simplifying the underlying mechanisms and for being too deterministic. In cases where drastic change is needed, current trends must be broken, but perhaps through measures other than those indicated by the above approaches. In other words, the cited approaches may overlook interesting opportunities and fail to urge necessary action. Backcasting is put forward as a more promising approach, especially for situations where great change is needed, However, it has been found in this study that backcasting and different forecasting approaches an complementary. The argument is that backcasting is mainly appropriate where current trends art: leading towards an unfavourable state. Therefore, forecasting methods are necessary because they inform the backcaster when backcasting is required. Finally, the paper discusses the use of different models in planning, primarily in the context of their role in the path analyses of backcasting scenarios.

• 47.
KTH, Superseded Departments, Infrastructure and Planning.
Bitumen ageing and hydrated lime1998Doctoral thesis, comprehensive summary (Other scientific)

This doctoral thesis consists of a literature review andfour papers describing experimental studies of the influence ofhydrated lime on bitumen ageing.

The literature review describes contemporary knowledge ofbitumen with respect to chemistry, rheology and modification.The relation between chemical composition and mechanicalbehaviour is discussed. In a section on rheology, a distinctionis made between fundamental mechanical properties, related toconstitutive equations, and empirical properties related solelyto the test methods used. Mechanisms of bitumen ageing aredescribed, with focus on oxidation, which is generally acceptedas most important. Various factors affecting ageing arediscussed as well as additives for the inhibition of bitumenageing: anti-oxidants, hydrated lime and polymers.

Since the beginning of the 1970s, hopes have been thathydrated lime, beside being a useful antistripping agent, alsomight work as an inhibitor of bitumen hardening. Theseexpectations appeared to be supported by the results of severallaboratory investigations. In studies presented in this thesis,laboratory ageing of bitumen was performed using standardisedmethods generally accepted to resemble real life conditionsduring production and service. The results show that under suchconditions, the anti-ageing capacity of hydrated lime is fairlymodest. However, it was also shown that using more severeageing conditions hydrated lime can produce a strikingreduction in the ageing index.

There are several pathways of bitumen oxidation, includingcatalysation. Different metal-containing compounds naturallyoccurring in bitumen, in particular various vanadium complexes,are supposed to catalyse bitumen ageing. One mechanism ofhydrated lime that has been suggested is the inhibition ofcatalyst-induced oxidation. Indications in favour of thisproposition were provided by an ageing study in which variousamounts of a vanadium-containing catalyst was added tobitumen.

The mechanical properties of bitumen are highly dependent onmolecular polarity. Since hydrated lime is a surface-activematerial, it is reasonable to expect that hydrated lime has asignificant impact on molecular configurations andstructure ofbitumen. Accordingly it appeared possible that hydrated limeaffects low temperature physical hardening and low temperaturemechanical properties such as the capacity of dissipation ofstored deformation energy. A study was performed using abending beam rheometer (BBR) for comparative tests of samplesthat were either neat or contained hydrated lime or a calciumcarbonate filler. However, the low temperature physicalhardening reflected no significant influence of thefillers.

KEYWORDS:bitumen, asphalt, ageing, additives, hydratedlime, rheology, IR-spectrometry, dynamic mechanical analysis(DMA), bending beam rheometer (BBR), vanadium chelates,literature study, low temperature physical hardening.

• 48.
KTH, Superseded Departments, Infrastructure and Planning.
Ökar samråden miljöhänsynen?2000Licentiate thesis, monograph (Other scientific)
• 49.
KTH, Superseded Departments, Infrastructure and Planning.
Influence of vibration frequency and amplitude on asphalt compaction2000Licentiate thesis, monograph (Other scientific)
• 50.
KTH, Superseded Departments, Infrastructure and Planning.
Laboratory studies of bitumen rejuvenator diffusion using FTIR-ATR2000Licentiate thesis, monograph (Other scientific)
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