13 research outputs found

    Life Cycle Costing in Road Planning and Management : A Case Study on Collision-free Roads

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    Construction of infrastructure does not only mean large capital investments but also future costs to operate and maintain these assets. Decision making in planning and design of roads will impact the need of future operation and maintenance activities. Additionally, infrastructure management is often under increasing pressure of aging structures, limited budgets and increased demands from public which require transparency in the decision making. Life cycle costing is a methodology that takes into account costs throughout an asset’s life cycle including investment, operation, maintenance and disposal. Despite the methodology’s existence for more than 40 years, the practical application is often reported to be scarce in both private and public sectors. Implementation in road planning and management means a high complexity where the life cycle costing can to be applied from early planning, design, construction and management in which all influence life cycle cost. Life cycle costing can also be applied in many different ways, level of detail and for different type of studies. For effective implementation of life cycle costing in road planning, design and management, different considerations need to be understood. In this thesis the application of life cycle costing has been studied through case study research. The main case selected was an investment to convert a single carriageway road to a, so called, sparse collision-free road. Through widening and separation between driving directions the traffic safety is significantly improved. However, in recent years increased operation and maintenance costs have been associated with the road type. Especially concerns regarding increased road user cost during road works have been expressed. This case was examined in two case studies from different perspectives. The first one was to study the implications on project appraisal and the second one examined the possibility to optimise pavement design. Results from cost benefit analyses based on established road appraisal techniques indicated that operation and maintenance related costs had limited impact on profitability. The second study also indicated that future cost can be influenced differently depending on criteria for optimal alternative. Based on economic analyses using established techniques, increased operation and maintenance liabilities appear to be of limited concern, in contrary to the perception. In future research this need to be set in context of road management with refined analysis in order to study implications for future management.QC 20141028</p

    Estimations of Delay Costs caused by Roadworks

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    When roadworks are performed, one of the impacts is delays in the traffic. Partly because of reduced speed limits past the work zones but mainly because of the facility's limited quality of service. This could result in significant delays for the road users with lost work and spare time as a consequence. The lost time in congestions could have been used more efficiently. It is therefore of interest to estimate these delays for different types of roadworks to calculate its macro economical impact. The estimations may be a factor in different types of planning, for example in roadwork planning, in work zone scheduling or in life cycle assessments. The estimations can be conducted using different methods, such as analytical, queuing theory or macrosimulation. However, to include the details of specific work zones an analysis method of higher detail is required. First to include varying geometric details, secondly due to the higher level of detail in the representation of the traffic. Therefore may microsimulation be a suitable analysis method. The purpose of this master thesis was to investigate microsimulations suitability for work zone analysis, by using the software AIMSUN. AIMSUN were different work zone types modeled, first of highways. Later was a 2-lane road modeled for which the traffic control was a fixed signal, then controlled by a simpler extension developed in C++ that simulated a flagger control. Using a developed helper program, the work zone models could be simulated for a large set of daily flow levels and heavy vehicle ratios. Together with corresponding results for normal conditions, it was possible to calculate the delays. The results were relationships between the total delays, for various heavy vehicle ratios. A concern with the results was deviations of the delays for different daily flows and heavy vehicle ratios. Even if the deviations will not have any greater impact on the total cost, they may be unwanted in decision models. Processing of the result may therefore be necessary. This master thesis has showed that microsimulation may be a suitable method to analyze work zone impacts. Using the high level of detail, work zones special character can be captured. Possible future work is to improve the reliability of results by performing validations of results with real work zone data to compare speeds, headways and queue lengths. Additional work may include to consider the diversion delays.NĂ€r vĂ€garbeten utförs uppkommer fördröjningar i trafiken. Delvis pĂ„ grund av reducerade hastigheter förbi arbetsomrĂ„det men i huvudsak pĂ„ grund av minskad framkomlighet. Det kan resultera i betydande fördröjningar för trafikanterna med förlorad arbets- och fritid som följd.  Den förlorade tiden i köer kunde dĂ„ ha anvĂ€nts effektivare. Det Ă€r dĂ„ av intresse att kunna uppskatta fördröjningarna vid olika typer av vĂ€garbeten för att berĂ€kna dess samhĂ€llsekonomiska pĂ„verkan. Uppskattningarna kan dĂ„ vara en faktor vid beslut inom olika typer av planering, till exempel vid vĂ€garbetsplanering, schemalĂ€ggning eller livscykelanalyser. För att göra dessa uppskattningar kan olika metoder anvĂ€ndas, till exempel analytiskt, med köteori eller makrosimulering. Men för att kunna inkludera detaljerna vid olika vĂ€garbeten krĂ€vs en analysmetod med högre detaljnivĂ„. Dels för att fĂ„ med geometriska detaljer, dels detaljnivĂ„n i representation av trafiken. DĂ„ kan mikrosimulering vara en lĂ€mplig metod. Syftet med det hĂ€r examensarbetat var att undersöka mikrosimulerings anvĂ€ndbarhet vid vĂ€garbetesanalyser, det genom att anvĂ€nda programvaran AIMSUN. I AIMSUN modellerades olika typer av vĂ€garbeten, först för motorvĂ€gar. Sedan modellerades en 2-fĂ€ltsvĂ€g dĂ€r trafikkontrollen dels sköttes av en skyttelsignal, sedan utvecklades ett enklare tillĂ€gg i C++ som simulerade en flaggvakt som istĂ€llet skötte trafikkontrollen. Med hjĂ€lp av ett utvecklat program kunde modellerna simuleras för en stor mĂ€ngd olika dygnsflöden och andel tung trafik. Tillsammans med motsvarande grundscenario kunde fördröjningarna berĂ€knas. Resultaten blev samband mellan totala fördröjningen under dagen beroende pĂ„ dygnsflödet, det för olika andelar tung trafik. Ett bekymmer med resultaten var variationer i fördröjningarna mellan olika dygnsflödesnivĂ„er och andelar tung trafik. Även om variationerna inte ger sĂ„ stort utslag pĂ„ totala kostnaden, sĂ„ kan variationerna vara icke önskvĂ€rda i till exempel beslutsmodeller. En viss bearbetning av resultaten kan dĂ„ vara nödvĂ€ndig. Det hĂ€r examensarbetet har visat att mikrosimulering kan vara en lĂ€mplig metod för att analysera vĂ€garbetens pĂ„verkan. Med dess höga detaljnivĂ„ har vĂ€garbetenas olika karaktĂ€r kunnat Ă„terskapas. Möjligt framtida arbete Ă€r att öka pĂ„litligheten i resultaten genom validation med trafikdata frĂ„n verkliga vĂ€garbeten med jĂ€mförelser mellan hastigheter, avstĂ„nd och kölĂ€ngder. Ytterligare arbete kan vara att uppskatta fördröjningar av att fordon vĂ€ljer omvĂ€gar för att undvika vĂ€garbetenas köer

    Follow-up study of a seven year design-build-operate-maintain project with performance requirements

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    Rapporten sammanfattar och analyserar totalentreprenaden pÄ vÀg N610, delen Brotorpet-HeagÄrd, efter sju Ärs kontraktstid. Objektet har följts upp frÄn framtagandet av förfrÄgningsunderlag till och med trafiköppning. Objektet har Àven ingÄtt som en del i IVA:s satsning pÄ att utveckla upphandlingsformer. Denna rapport fokuserar pÄ det tekniska utfallet under de sju Är som funktionellt ansvar kontrakterats. Utfallet analyseras mot bakgrund av de förutsÀttningar som gavs i samband med upphandlingen, sÀrskilt de funktionella kraven och utformningen av dÀrtill kopplat bonus- och vitessystem. Objektet Àr ett av ett fÄtal objekt som pÄ detta sÀtt följts upp sÄ att idéer och resultat kan fÄ spridning och anvÀndas i den utveckling av upphandlingsformer som mÄste Àga rum. SÀrskilt viktigt Àr detta i ljuset av Trafikverkets pÄgÄende satsningar pÄ totalentreprenader. Denna rapport bör lÀsas mot bakgrund av att branschen för tio Är sedan hade ringa erfarenhet av totalentreprenader och objektet i stora delar kan betecknas som ett pilotprojekt dÀr bÄde bestÀllare och entreprenör har lÀrt sig efter hand. Ur bÄde ett tekniskt och ekonomiskt perspektiv förefaller entreprenaden lyckad. Entreprenaden verkar inte ha blivit dyrare Àn vad som kan förvÀntas medan den tekniska prestandan Àr bra. Det konstateras att vissa mÀt- och verifieringsmetoder Àr behÀftade med brister men att dessa brister inte pÄ nÄgot avgörande sÀtt pÄverkat resultatet negativt.This report concludes and analyses a Design-Build procurement on road N610, north of the city of Halmstad in Sweden, after a seven year contract period with performance requirements. This object has been followed up by others from the stage of preparing the procurement documents to the stage of opening the road for traffic. The object has also been part of the efforts of the Royal Swedish Academy of Engineering Sciences (IVA) efforts to facilitate development of procurement forms. This report focuses on the more technical aspects of the project, in particular the relationship between procurement design and the outcome in terms of measured technical parameters and the economical result of the bonus-malus system. This project is one of few that have been followed up to document and share ideas and results in the current development of procurement forms so desperately needed. In Sweden, the project should also be used in the context of the substantial share of contracts today offered as Design-Build or even with extended responsibilities for maintenance or operations (performance contracts). Ten years ago, however, the experience was limited of these contracts and it is evident that this project has been a learning process for both contractor and client. From a technical and economical point of view the project can be regarded as successful. The cost was normal and the technical outcome good, or even in some respect very good. Moreover, it can be concluded that there are requirements and measurement methods that are unreliable but this cannot be proven to have influenced the result in a negative way

    Energy efficiency of pavements for heavy vehicles : A literature survey

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    Det Ă€r viktigt att studera trafikens energieffektivitet eftersom relativt smĂ„ förĂ€ndringar kan fĂ„ stora effekter rĂ€knat över vĂ€gens hela livslĂ€ngd. Fordons fĂ€rdmotstĂ„nd studerades dĂ€rför i detta projekt och i synnerhet dess rullmotstĂ„nd - den del av fĂ€rdmotstĂ„ndet som kopplas till interaktionen mellan dĂ€ck och vĂ€gyta. Beroende pĂ„ körförhĂ„llande och fordonstyp motsvarar rullmotstĂ„ndet ca 5–40 procent av det totala fĂ€rdmotstĂ„ndet. Det har observerats i tidigare forskning att ytegenskaper sĂ„som textur (Mean Profile Depth, MPD) och ojĂ€mnheter (International Roughness Index, IRI) har en inverkan pĂ„ rullmotstĂ„ndet. Hur stor betydelsen Ă€r varierar dock mellan olika analyser. Variationen i resultaten kan bero pĂ„ svĂ„righeter att utföra jĂ€mförbara mĂ€tningar men ocksĂ„ pĂ„ att det kan vara svĂ„rt att isolera texturens och ojĂ€mnhetens pĂ„verkan i mĂ€tningar. Även belĂ€ggningens styvhet och nedböjning kan i viss mĂ„n pĂ„verka rullmotstĂ„ndet. Storleken pĂ„ denna inverkan Ă€r dock oklar. Effekterna av dessa parametrar anses Ă€nnu inte vara klarlagda. Ju högre fĂ€rdmotstĂ„nd ett fordon har, desto högre Ă€r energibehovet och dĂ€rmed brĂ€nslebehovet. Tidigare studier har genomförts för att ta reda pĂ„ hur fordons brĂ€nsleförbrukningen varierar mellan körning pĂ„ betong- och asfaltvĂ€gar. FastĂ€n flera av dessa studier indikerar att brĂ€nsleförbrukningen skulle vara högre pĂ„ asfaltvĂ€gar jĂ€mfört med betongvĂ€gar rĂ„der osĂ€kerheter eftersom flertalet inte tagit hĂ€nsyn till belĂ€ggningarnas ytegenskaper. Detta Ă€r en betydande brist eftersom belĂ€ggningarnas egenskaper kan ge betydande inverkan pĂ„ rullmotstĂ„ndet. En minskning av rullmotstĂ„ndet pĂ„ högtrafikerade vĂ€gar leder till större brĂ€nslebesparingar. Dessa Ă„tgĂ€rder behöver dock vĂ€gas mot den insats av energi som behövs för att Ă„stadkomma ett lĂ€gre rullmotstĂ„nd. JĂ€mförda fallstudier visar ocksĂ„ att det oftast Ă€r fördelaktigt att investera mer energi vid sjĂ€lva underhĂ„llsĂ„tgĂ€rden om den Ă„tgĂ€rden kan resultera i ett lĂ€gre rullmotstĂ„nd, gentemot en mindre underhĂ„llsĂ„tgĂ€rd som resulterar i ett nĂ„got högre rullmotstĂ„nd.It is important to study traffic energy efficiency since small changes can have major effects over the road’s service life. Vehicle driving resistance was studied in this project and, in particular, its rolling resistance - the part of the driving resistance connected to the interaction between tyre and road surface. Depending on driving conditions and vehicle type, the rolling resistance corresponds to 5–40 percent of the total driving resistance. It has been observed in studies that road surface properties such as texture (Mean Profile Depth, MPD) and unevenness (International Roughness Index, IRI) have an impact on rolling resistance. However, the significance varies between different analyses. The variation in the results may be due to difficulties in performing comparable tests and that it is often difficult to isolate the effect of texture and unevenness during the tests. In addition, pavement stiffness and deflection may also have an effect on rolling resistance. However, the impact from these parameters is unclear. The higher the driving resistance of a vehicle, the higher the energy needed. Earlier studies examined how vehicle fuel consumption varied between driving on concrete roads and asphalt roads. Although several of these studies showed a lower fuel consumption when driving on concrete roads, most of them did not consider the pavement surface characteristics. This is a significant shortcoming because pavement surface characteristics can have a considerable effect on rolling resistance. Reducing rolling resistance on high-traffic volume roads will lead to greater fuel savings. However, these measures need to be weighed against the amount of energy needed to achieve a lower rolling resistance. Compared case studies also show that it is often beneficial to invest more energy on the maintenance measure itself if it can lead to a lower rolling resistance, compared to a less comprehensive maintenance measure leading to a higher rolling resistance

    Design And Evaluation Of A Fully Adaptive Antenna For Telecommunication Systems

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    An adaptive antenna for the DCS-1800 mobile telephony system has been designed and evaluated. The antenna is working in uplink only and has a multiplexity of two channels per frequency and timeslot. The array antenna has a circular structure and the complex weights are calculated using the sample matrix inversion method (SMI). Evaluations of the adaptive antenna in an outdoor environment show promising improvement of the carrier-to-interfererratio (C/I) of more than 30 dB. Measurements of bit-error-rate (BER) for different angular separation of the mobiles show that for an input C/I Âł -10 dB the minimum angular separation for approximately 0% BER is less than 4 degrees. INTRODUCTION The use of adaptive antennas in mobile communication systems offers a possibility to increase the system capacity. To exploit the benefits of using adaptive base station antennas, a testbed project commenced 1994 consisting of groups at the Signals and Systems group at Uppsala University and Ericsson Radio..

    Projektrapport - DUKAT

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    Det finns en stor brist pĂ„ empirisk forskning om effekten av vĂ€garbetsomrĂ„den pĂ„ kapaciteten hos motorvĂ€gar. Denna studie försöker fylla en liten lucka genom att sammanstĂ€lla kunskap om kapacitet pĂ„ motorvĂ€g vid vĂ€garbetsomrĂ„den och de villkor och variabler som pĂ„verkar denna förmĂ„ga i verkliga situationer. MĂ„let med denna studie kan dela in i tre olika delmĂ„l: 1. uppskatta skillnaden i kapacitet för olika utformningar av vĂ€garbetsomrĂ„den jĂ€mfört med standardsituationen. 2 förklara skillnader i kapacitet genom att analysera situationsspecifika variabler. 3 analysera effekten av externa variabler som pĂ„verkar kapaciteten pĂ„ motorvĂ€gar vid olika utformningar av vĂ€garbetsomrĂ„den. De utformningar av vĂ€garbetsomrĂ„den som Ă€r de mest frekvent nĂ€rvarande i Sverige under de senaste Ă„ren och dĂ€rför analyseras i denna studie Ă€r: ‱stĂ€ngning av vĂ€grenen ‱avsmalning av körfĂ€lten pĂ„ motorvĂ€g med 2 kf ‱avsmalning av körfĂ€lten pĂ„ motorvĂ€g med 3 kf ‱reduktion av antalet körfĂ€lt pĂ„ motorvĂ€g med 2 kf ‱reduktion av antalet körfĂ€lt pĂ„ motorvĂ€g med 3 kfDrift- och UnderhĂ„llseffekter pĂ„ kapacitet och trafikföring (DUKAT

    Indicators for the Swedish Transport Administration's follow-up of maintenance on paved roads : delivery qualities for the transport policy goals

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    Ett sÀtt för Trafikverket att följa upp effekterna av underhÄllet pÄ de statliga vÀgarna Àr genom att anvÀnda sig av indikatorer. De indikatorer som beskrivs i denna rapport benÀmns som andra ordningens indikatorer och byggs upp av underliggande data. Indikatorerna som vi valt att arbeta med ska pÄ ett allsidigt och transparent sÀtt beskriva hur Trafikverket uppfyller leveranskvaliteten för punktlighet, kapacitet, robusthet, anvÀndarbarhet, sÀkerhet samt miljö och hÀlsa.  I denna förstudie sammanfattar vi en kunskapsöversikt för valda indikatorer och förslag pÄ hur de kan implementeras i Trafikverkets pavement management system. De indikatorer som vi arbetar med Àr SÀkerhet, Komfort, Strukturellt tillstÄnd, RullmotstÄnd, Buller, Luftkvalitet, Godsskador, Ytskador, Fordonsslitage och slutligen en indikator för HÀlsa. Det finns mÄnga aspekter att ta hÀnsyn till dÄ en indikator introduceras. Den absolut viktigaste Àr, bortsett frÄn att den Àr validerad, att den fÄr acceptans och anvÀnds. Det finns mÄnga sÀtt att anvÀnda en indikator och att enbart titta pÄ absoluta vÀrden Àr svÄrt för en sammansatt indikator. Relativa skillnader vid Ärliga uppföljningar Àr att föredra för att avgöra om strategier fÄr avsedd effekt.One way for the Swedish Transport Administration (STA) to follow up the effects of maintenance on state roads is by using indicators. The indicators described in this report are defined as second-order indicators and are built up using underlying data. The indicators describe, in a comprehensive and transparent way, how the STA meets delivery quality parameters for punctuality, capacity, robustness, usability, safety, and environment and health.  In this feasibility study, a knowledge overview of the selected indicators is presented. Suggestions are also given on how the indicators can be implemented in the STA's pavement management system. The indicators studied were Safety, Comfort, Structural Condition, Rolling Resistance, Noise, Air Quality, Goods Damage, Surface Damage, Vehicle Wear, and Health Risk. Many aspects must be considered when introducing an indicator. Along with validation, it is extremely important that the indicator will be accepted and used. There are many ways to use an indicator, however, it is not ideal to only consider absolute values for a composite indicator. Relative differences in annual follow-ups are preferable to determine whether strategies have the intended effect

    Experimental Evaluation of an Adaptive Antenna for a TDMA Mobile Telephony System

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    Measurements of an adaptive DCS-1800 base station antenna, used in uplink only, are presented and analysed. Both laboratory measurements and outdoor field trials have been performed. The antenna is improving the C/I ratio more than 30 dB. Calculations using measured data, assuming downlink performance equal to that of the uplink, show a spectral efficiency gain of 6 over present base station systems
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