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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Modelling of Traffic Performance for Swedish Roads and Motorways

Strömgren, Per January 2016 (has links)
This thesis consists of five scientific articles oriented towards capacity. Managing capacity constraints with associated delays is a big issue at new design as well as at trimming existing traffic facilities. In larger Swedish cities these challenges have become more and more important as a result of growing traffic demand due to rapid population increase.Models for estimating capacity and delay are available, but not many are calibrated for Swedish conditions due to the high effort required. This thesis documents development and calibration of new models for motorway links, entry and exit lanes and weaving areas and an developed space-time model with the ability to calculate queue length, delay, etc.The first article is focused on identifying weaknesses in the former Swedish capacity method for motorways, and development of new models overcoming these shortcomings. The development includes new models for jam density at queue, capacity in weaving areas and fundamental flow-density relationships for 15 different highway types for inclusion in the new Swedish capacity manual.The second article describes the development of a Swedish motorway space-time model to estimate travel times and queues in oversaturated conditions based on the American FREEVAL model in Highway Capacity Manual 2010 (HCM 2010). Calibration and validation of the model has been performed with data from the Motorway Control System (MCS) in Stockholm. A good correspondence was obtained for most cases, but further calibration and validation efforts are required for entry and exit lanes.The third article describes further development of the intersection model in the Swedish microscopic model “Rural Traffic Simulator (RuTSim). This is a continuation of the work documented in the author’s licentiate thesis published in 2002. The development focused on simulation of intersections using a new concept on lane use not included in the old RuTSim model. The model describes Swedish rural intersections with flared approaches providing a non-discreet lane use due to vehicle types in queue. New data for calibration and validation data was also generated. The validation results showed good correspondence between simulated and empirical delay results. The new intersection model is now implemented in RuTSim, providing new tools for estimation of capacity, delay and queue length already included in Swedish guidelines and capacity manuals/software (Capcal).The fourth article describes the development of a new capacity model for roadwork zones. Focus is on the resulting capacity of one lane due to several reduction factors. These factors include impacts of closed road shoulders, reduction of number of lanes, diversion of traffic to the opposite carriageway, commuting traffic, length of work zone, lane width and type of road work. The first two correction factors were successfully validated in a full-scale test on the E6 motorway in Gothenburg.The fifth article describes development and implementation of a new harmonization algorithm for MCS systems on motorways designed to increase bottleneck capacity and throughput. Two different models were developed, one of which was implemented in the existing MCS system on E4 Södertäljevägen south of Stockholm. Full-scale trials were carried out with a model based on trigger levels in terms of flow. The second model based on the difference in the variance of speed during two following time periods was tested offline also with very good results. / <p>QC 20160429</p>
2

Rigid barrier or not? : Machine Learning for classifying Traffic Control Plans using geographical data

Wallander, Cornelia January 2018 (has links)
In this thesis, four different Machine Learning models and algorithms have been evaluated in the work of classifying Traffic Control Plans in the City of Helsingborg. Before a roadwork can start, a Traffic Control Plan must be created and submitted to the Traffic unit in the city. The plan consists of information regarding the roadwork and how the work can be performed in a safe manner, concerning both road workers and car drivers, pedestrians and cyclists that pass by. In order to know what safety barriers are needed both the Swedish Association of Local Authorities and Regions (SALAR) and the Swedish Transport Administration (STA) have made a classification of roads to guide contractors and traffic technicians what safety barriers are suitable to provide a safe workplace. The road classifications are built upon two rules; the amount of traffic and the speed limit of the road. Thus real-world problems have shown that these classifications are not applicable to every single case. Therefore, each roadwork must be judged and evaluated from its specific attributes. By creating and training a Machine Learning model that is able to determine if a rigid safety barrier is needed or not a classification can be made based on historical data. In this thesis, the performance of several Machine Learning models and datasets are presented when Traffic Control Plans are classified. The algorithms used for the classification task were Random Forest, AdaBoost, K-Nearest Neighbour and Artificial Neural Network. In order to know what attributes to include in the dataset, participant observations in combination with interviews were held with a traffic technician at the City of Helsingborg. The datasets used for training the algorithms were primarily based on geographical data but information regarding the roadwork and period of time were also included in the dataset. The results of this study indicated that it was preferred to include road attribute information in the dataset. It was also discovered that the classification accuracy was higher if the attribute values of the geographical data were continuous instead of categorical. In the results it was revealed that the AdaBoost algorithm had the highest performance, even though the difference in performance was not that big compared to the other algorithms.
3

Estimations of Delay Costs caused by Roadworks

Wennström, Jonas January 2010 (has links)
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. / När vägarbeten utförs uppkommer fördröjningar i trafiken. Delvis på grund av reducerade hastigheter förbi arbetsområdet men i huvudsak på 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 då ha använts effektivare. Det är då av intresse att kunna uppskatta fördröjningarna vid olika typer av vägarbeten för att beräkna dess samhällsekonomiska påverkan. Uppskattningarna kan då vara en faktor vid beslut inom olika typer av planering, till exempel vid vägarbetsplanering, schemaläggning eller livscykelanalyser. För att göra dessa uppskattningar kan olika metoder användas, till exempel analytiskt, med köteori eller makrosimulering. Men för att kunna inkludera detaljerna vid olika vägarbeten krävs en analysmetod med högre detaljnivå. Dels för att få med geometriska detaljer, dels detaljnivån i representation av trafiken. Då kan mikrosimulering vara en lämplig metod. Syftet med det här examensarbetat var att undersöka mikrosimulerings användbarhet vid vägarbetesanalyser, det genom att använda programvaran AIMSUN. I AIMSUN modellerades olika typer av vägarbeten, först för motorvägar. Sedan modellerades en 2-fältsväg där trafikkontrollen dels sköttes av en skyttelsignal, sedan utvecklades ett enklare tillägg i C++ som simulerade en flaggvakt som istället skötte trafikkontrollen. Med hjälp av ett utvecklat program kunde modellerna simuleras för en stor mängd olika dygnsflöden och andel tung trafik. Tillsammans med motsvarande grundscenario kunde fördröjningarna beräknas. Resultaten blev samband mellan totala fördröjningen under dagen beroende på dygnsflödet, det för olika andelar tung trafik. Ett bekymmer med resultaten var variationer i fördröjningarna mellan olika dygnsflödesnivåer och andelar tung trafik. Även om variationerna inte ger så stort utslag på totala kostnaden, så kan variationerna vara icke önskvärda i till exempel beslutsmodeller. En viss bearbetning av resultaten kan då vara nödvändig. Det här examensarbetet har visat att mikrosimulering kan vara en lämplig metod för att analysera vägarbetens påverkan. Med dess höga detaljnivå har vägarbetenas olika karaktär kunnat återskapas. Möjligt framtida arbete är att öka pålitligheten i resultaten genom validation med trafikdata från verkliga vägarbeten med jämförelser mellan hastigheter, avstånd och kölängder. Ytterligare arbete kan vara att uppskatta fördröjningar av att fordon väljer omvägar för att undvika vägarbetenas köer.
4

Trafikinformation i realtid i samband med vägarbete / Traffic Information in real time in connection with road work

Almqvist, Andreas, Simervir, Sandhu January 2012 (has links)
I rapporten har vi förklarat vilka problem som kan uppstå med dagens teknik och vilka eventuella lösningar som man kan förbättra med tiden. Med hjälp av Trafikverket har vi genomfört detta examensarbete. Vi hade fått tydliga direktiv från Trafikverket gällande examensarbetets syfte. Det gjorde det enkelt för oss att avgränsa arbetet efter de riktlinjer som var angivna och möjliga att genomföra. Studiens syfte var att förstå varför det inte går ge ut relevant trafikinformation. I dagsläget har man tekniken för ett väl fungerande system. Ett system där man enkelt kan få realtidsinformation i samband med trafiken, vägarbeten och eventuella hinder. I rapporten har vi även sammanfattat alla navigationssystem som man kan ha användning av som trafikant. Vi har gjort en omvärldsanalys på hur man i andra länder ger ut trafikinformation och hur de står sig jämtemot Sveriges trafikinformationssystem. För vårt examensarbete har vi använt oss av diverse olika rapporter och intervjuer. Detta tillsammans med personer som har kunskap inom området. Vi har även använt oss av åtskilliga hemsidor för att inhämta information. Rekommendationer för examensarbetet kommer att beskrivas genom fem teman. I rapporten har vi utfört en mängd olika intervjuer som vi sammanställt till teman. Teman var utformade efter det vi kände var mest relevant från intervjuerna. Våra teman speglar bilden av vad vi har lagt vikt med detta examensarbete. / In this report, we have explained the problems that may occur with today's technology and what possible solutions to improve with time. With the help of the Swedish Transport Administration, we have implemented this thesis. We got the clear directions from the Swedish Transport Administration regarding purpose of this thesis. This made it easy for us to delineate our work after the guideline that was definer. The study's purpose was to try to understand why you can´t give out the relevant traffic information. Today we have the technology create a well smooth operation system. A system where you can easily get real-time information related to traffic, road works and obstructions. In this report we have summarized all the navigation system that you could use as a road user. We have done an analysis of how other countries give out their traffic information and how good they are against the Swedish traffic information system. For our thesis we have used various of different reports and interviews. The interviews have been with people who have knowledge in the field. We have also used numerous websites to gather information. Recommendations for the thesis will be described through five themes. In this report, we have conducted a variety of interviews that we have compiled for themes. Themes were designed for what we felt was most relevant from the interviews. Our themes are a mirror image of what we thought was the most relevant part in our thesis.
5

Byggarbetsmiljösamordnares syn på utbildning, erfarenhet och kompetens för upprättande av arbetsmiljöplan och skydd vid etablering av anläggning på eller vid väg.

Wagner, Camilla January 2017 (has links)
Bakgrund: Arbetsmiljöföreskrifter ställer krav på erforderlig utbildning, erfarenhet och kompetens för byggarbetsmiljösamordnare vidför planering, projektering och utförande för att kunna verka i dessa roller. Det finns dock brister i kunskap om hur utbildning, erfarenhet och kompetens kan påverka skyddet vid anläggningsverksamhet som föregås vid eller på väg. Syfte: Det första syftet är att få en uppfattning om hur de som arbetar som byggarbetsmiljösamordnare vidför planering och projektering resonerar kring upprättande av arbetsmiljöplan som riskhanteringsverktyg. Det andra syftet är att undersöka hur byggarbetsmiljösamordnare vidför utförande hanterar och tolkar arbetsmiljöplanen ur riskhänseende. Det tredje syftet är att ta reda på vilken utbildningsomfattning och inriktning på utbildning byggarbetsmiljösamordnare anser att det finns behov avför, samt vilket intervall som behövs för kontinuerlig fortbildning. Det fjärde syftet är att utvärdera huruvida byggarbetsmiljösamordnare anser att mentorskap bör rekommenderas som en del i lärandet.   Metod/Genomförande: Magisteruppsatsen har genomförts som en semistrukturerad kvalitativ intervju med de personer som verkar som byggarbetsmiljösamordnare för planering, projektering och utförande samt trafikanordningsansvarig. Observationer har gjorts vid anläggningsarbete på företag benämnt nr 1, samt litteraturstudier.   Resultat: Studien visar att det finns behov av olika inriktningar vid utbildningsgenomförande, samt att det finns behov av repetitionsutbildning. Utbildningarna bör innehålla både teoretiska och praktiska moment, alternativt lärande genom mentorskap. Praktisk anknytning har Det framkom också att praktisk anknytning har framkommit har stor betydelse för genomförande av god riskhantering, för byggarbetsmiljösamordnare för planering, projektering och utförande.   Slutsats: Studien visar att det finns behov av att utveckla själva upplägget och inriktningen av utbildningar för byggarbetsmiljösamordnare. Idag erbjuds enbart teoretiskt inriktade utbildningar. Det vore betydelsefullt att kunna tillhandahålla mentorskap som del av utbildningen.  Respondenterna Repetitionsutbildningar anser att repetitionsutbildningarrespondenterna är viktiga som ett led i att upprätthålla och vidareutveckla riskhantering och säkerhet.   Nyckelord: Byggarbetsmiljösamordning, anläggningsarbete, vägarbetare, arbetsmiljöplan, riskhantering, BAS P, BAS U. / Abstract Background: Building work environment co-ordinators Safety Coordinators are responsible for planning, designing projecting and executionperformance at the construction site. This report aims to look into their view on education, experience and competence required to work in these roles. Aim: The first aim is to understand how the building workenvironment co-ordinatorsSafety Coordinators for planning and designing projecting think about resonate around the creation of a work environment plan used as a risk management. tool. The second aim is to examine how building workenvironment co-ordinators Safety Coordinators for execution performing, is handling and interpret the work environment plan as risk management tool. The third aim is to find out in what extent they consider it necessary, as well as what level of education they need. The fourth aim is to evaluate if there is a need for mentoring as a part of education. Method: This one year master hasthesis has been conducted as a qualitative study with individual interviews with four building  work environment co-ordinators construction workers, and one traffic planning co-ordinator. constructor. It has also included observations at different construction works at company 1. A data literature analysis was also conducted. Results: The study shows that there is a need for different directions in the implementation of training, and that there is a need to repeat the training sessions. The sessions should be a combination of theoretical and practical moments, alternative learning through mentoring. Practical connection has been found to be of great importance for the implementation of good risk management, for building work environment co-ordinators construction environmental coordinators for planning, designing and execution. Conclusion: The study shows that there is a need to develop structure and focus of education for the building work environment co-ordinators construction environment coordinator and traffic planning co-ordinator. Today, only theoretically oriented trainings are offered. It would be of great importance to provide mentoring as part of the education. Repeated training is considered to be important as part of maintaining and further developing risk management and security. Key Words: Construction work coordination, Construction work, roadwork, road worker, workenvironment plan, riskmanagement, BAS P, BAS U.

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