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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.
21

Most nad místní komunikací a potokem / Bridge over a local road and a brook

Tichavská, Andrea January 2015 (has links)
The purpose of the master thesis is the design of the concrete highway bridge by European standards. The highway is situated on two independent prestressed load-bearing structures with cross-section area of constant dimensions over its length. The bridge deck is built on a falsework considering its proportions and obstacles under the bridge. The thesis contains the design and the assessment of the load-bearing structure in longitudinal and transverse direction including the calculation of cross beams and an anchorage zone.
22

Temporary barriers reduce rubbernecking and external distraction on roadways

Colon, Nicholas 01 May 2013 (has links)
The purpose of the current study was to empirically examine the effects of accident scenes on eye movement as well as driving behavior. Fifty-four participants drove in a driving simulator wearing a head-mounted eye-tracker in three experimental drives, one of which had an accident scene. The participants were put into one of three different conditions (no barrier, partial barrier, or full barrier). The results showed significant main effects of distraction (accident vs. no accident) on dwell frequency and duration, average speed, and root mean square error of the steering wheel angle during the drive with the accident scenes. In addition, the results also showed significant interaction effects between distraction and type of barrier (no, partial, or full) on dwell frequency and duration. The full barrier condition had the biggest effect on decreasing dwell duration and frequency. The findings support the Salience Effort Expectancy Value (SEEV) model of attention and previous research stating objects high in salience attract attention (Wickens & Horrey, 2008; Itti & Koch, 2000). These findings also support previous research by Mayer, Caird, Milloy, Percival, & Ohlhauser (2010) stating that drivers drive in the safest manner (lowest passing speed) when an emergency vehicles are present with the emergency lights on. Temporary barriers could be used to help decrease the effects of rubbernecking on highways when an accident scene is present (Masinick & Teng, 2004; Potts, Harwood, Hutton, & Kinzel, 2010)
23

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>
24

The relationship between traffic congestion and road accidents : an econometric approach using GIS

Wang, Chao January 2010 (has links)
Both traffic congestion and road accidents impose a burden on society, and it is therefore important for transport policy makers to reduce their impact. An ideal scenario would be that traffic congestion and accidents are reduced simultaneously, however, this may not be possible since it has been speculated that increased traffic congestion may be beneficial in terms of road safety. This is based on the premise that there would be fewer fatal accidents and the accidents that occurred would tend to be less severe due to the low average speed when congestion is present. If this is confirmed then it poses a potential dilemma for transport policy makers: the benefit of reducing congestion might be off-set by more severe accidents. It is therefore important to fully understand the relationship between traffic congestion and road accidents while controlling for other factors affecting road traffic accidents. The relationship between traffic congestion and road accidents appears to be an under researched area. Previous studies often lack a suitable congestion measurement and an appropriate econometric model using real-world data. This thesis aims to explore the relationship between traffic congestion and road accidents by using an econometric and GIS approach. The analysis is based on the data from the M25 motorway and its surrounding major roads for the period 2003-2007. A series of econometric models have been employed to investigate the effect of traffic congestion on both accident frequency (such as classical Negative Binomial and Bayesian spatial models) and accident severity (such as ordered logit and mixed logit models). The Bayesian spatial model and the mixed logit model are the best models estimated for accident frequency and accident severity analyses respectively. The model estimation results suggest that traffic congestion is positively associated with the frequency of fatal and serious injury accidents and negatively (i.e. inversely) associated with the severity of accidents that have occurred. Traffic congestion is found to have little impact on the frequency of slight injury accidents. Other contributing factors have also been controlled for and produced results consistent with previous studies. It is concluded that traffic congestion overall has a negative impact on road safety. This may be partially due to higher speed variance among vehicles within and between lanes and erratic driving behaviour in the presence of congestion. The results indicate that mobility and safety can be improved simultaneously, and therefore there is significant additional benefit of reducing traffic congestion in terms of road safety. Several policy implications have been identified in order to optimise the traffic flow and improve driving behaviour, which would be beneficial to both congestion and accident reduction. This includes: reinforcing electronic warning signs and the Active Traffic Management, enforcing average speed on a stretch of a roadway and introducing minimum speed limits in the UK. This thesis contributes to knowledge in terms of the relationship between traffic congestion and road accidents, showing that mobility and safety can be improved simultaneously. A new hypothesis is proposed that traffic congestion on major roads may increase the occurrence of serious injury accidents. This thesis also proposes a new map-matching technique so as to assign accidents to the correct road segments, and shows how a two-stage modelling process which combines both accident frequency and severity models can be used in site ranking with the objective of identifying hazardous accident hotspots for further safety examination and treatment.
25

Dopady PPP projektů na státní a soukromou sféru

Kobelka, Tomáš January 2010 (has links)
In thesis the author writes about PPP projects. After theretical introduction about them he describes advantages and disadvantages of PPP projects. Then he continues writing concentrating on his main goal, impacts of PPP projects on public and private sector. He includes the relation between PPP projects and keynes and transactional multiplier, public finance and sovereign rating. In practial part the author decribes impacts of motorway M6 in Hungary and highway D3/R3 in Czech Republic.
26

Untersuchung des Blickverhaltens von Kraftfahrern auf Autobahnen

Hristov, Borislav 08 April 2010 (has links) (PDF)
Über 90% der Informationsaufnahme beim Fahren erfolgt über den visuellen Sinneskanal. Das Auge ist das einzige fernorientierte Sinnesorgan, das über die Blickbewegungen gezielt ausrichtbar ist und die Erfassung räumlich voraus liegender Objekte ermöglicht. Somit spielt das Blickverhalten der Kraftfahrer eine zentrale Rolle beim Steuern eines Fahrzeugs. Da die Informationsaufnahme und -verarbeitung die Grundlage für Handlungsentscheidungen, ihre Realisierung und Kontrolle im Straßenverkehr bilden, bestimmt das Blickverhalten des Kraftfahrers weitestgehend sein Fahrverhalten und ist dadurch auch für die Verkehrssicherheit von zentraler Bedeutung. Mit Hilfe moderner Messtechnik lassen sich die Blickbewegungen genau registrieren und das Blickverhalten kann beim Autofahren exakt erfasst werden. Dadurch stellt die Analyse des Blickverhaltens ein neues Verfahren dar, mit dem der wahrnehmungspsychologische Faktor in der Wechselwirkung zwischen Fahrer, Fahrzeug und Straße berücksichtigt werden kann. Das Blickverhalten der Fahrer ist ein hochselektiver dynamischer Vorgang, durch den eine präzise Wahrnehmung von beweglichen bzw. unbeweglichen Objekten, Geschwindigkeiten und räumlichen Ausdehnungen gewährleistet ist. Die Analyse des Blickverhaltens ermöglicht sowohl den zeitlichen als auch den räumlichen Verlauf des detaillierten Informationszuflusses zusammen mit den Aufmerksamkeitsverlagerungen zu erforschen. Wo und in welchem Zeitpunkt der Fahrer detailliert hinblickt, kann mithilfe der Blickverhaltensanalyse ermittelt werden. In der Literatur sind verschiedene Blickverhaltensmaße vorhanden, mit denen das zeitliche Verhalten der visuellen Aufmerksamkeitsverteilung, die räumliche Konzentration des Blickes und die Intensität der Informationsaufnahme untersucht und interpretiert werden können. In der vorliegenden Arbeit werden aus dem breiten Spektrum dieser Maße diejenigen ausgewählt, die bezüglich der gesuchten Abhängigkeiten am aussagekräftigsten sind. Das Blickverhalten der Kraftfahrer wird in erheblichem Maße von der Streckenge-ometrie bestimmt. Aus der Forschung ist bekannt, dass die Verhältnisse beim Lenken eines Fahrzeugs entlang geraden Strecken und innerhalb von Kurven bezüglich der Beanspruchung des Fahrers und der Blickkonzentration nicht gleich sind. In Kurven ist die Belastung höher im Vergleich zu den Geraden und das führt zu einer gesteigerten Aufmerksamkeit. Das Blickverhalten in Links- und Rechtskurven charakterisiert sich mit bestimmten Blickmustern, die sich voneinander deutlich unterscheiden. Diesbezüglich werden entsprechende Untersuchungen und Analysen auch unter Einbeziehung der vorhandenen Sichtweite durchgeführt. Der Einfluss der streckencharakteristischen Parameter auf das Fahrverhalten und das Unfallgeschehen ist auf dem Gebiet des Straßenentwurfs seit langer Zeit Untersuchungsgegenstand zahlreicher Forschungsarbeiten. Auf Autobahnen sind jedoch nur wenige solche Untersuchungen vorhanden und ein Forschungsbedarf liegt auch diesbezüglich vor. In der Dissertation wurde die BAB A72 zwischen Hof und Chemnitz untersucht, die eine der ältesten Autobahnen Deutschlands ist und für die bekannt ist, dass sie Sicherheitsprobleme hat. Diese Bundesautobahn, die ursprünglich als Regionalautobahn sehr geländeangepasst trassiert worden ist, wurde im Zeitraum von 1990 bis 1995 grundhaft ausgebaut. Die Trasse ist unverändert geblieben und die Gradiente und der Querschnitt sind verbessert worden. Dadurch sind die Geschwindigkeiten deutlich gestiegen. So ein Ausbau kann zu Disproportionen in der räumlichen Linienführung führen. Auf der Autobahn A72 sind in einigen Abschnitten solche Disproportionen vorhanden. Ausdruck dafür ist das überdurchschnittlich hohe Unfallgeschehen. Die Verkehrssicherheit hat eine vorrangige Bedeutung für den Bau und den Betrieb jeder Straße. In der Arbeit wird durch das Blickverhalten von Fahrern mit einer neu entwickelten Methodik versucht, die Gründe für unsichere Abschnitte anders als mit den klassischen Methoden zu erforschen. Im Ergebnis werden Empfehlungen für einen Kurvenmindestradius und eine psychologische Mindestsichtweite untermauert.
27

Multicriteria analysis and GIS application in the selection of sustainable motorway corridor

Belka, Kamila January 2005 (has links)
Effects of functioning transportation infrastructure are receiving more and more environmental and social concern nowadays. Nevertheless, preliminary corridor plans are usually developed on the basis of technical and economic criteria exclusively. By the time of environmental impact assessment (EIA), which succeeds, relocation is practically impossible and only preventative measures can be applied. This paper proposes a GIS-based method of delimiting motorway corridor and integrating social, environmental and economic factors into the early stages of planning. Multiple criteria decision making (MCDM) techniques are used to assess all possible alternatives. GIS-held weighted shortest path algorithm enables to locate the corridor. The evaluation criteria are exemplary. They include nature conservation, buildings, forests and agricultural resources, and soils. Resulting evaluation surface is divided into a grid of cells, which are assigned suitability scores derived from all evaluation criteria. Subsequently, a set of adjacent cells connecting two pre-specified points is traced by the least-cost path algorithm. The best alternative has a lowest total value of suitability scores. As a result, the proposed motorway corridor is routed from origin to destination. It is afterwards compared with an alternative derived by traditional planning procedures. Concluding remarks are that the location criteria need to be adjusted to meet construction requirements as well as analysis process to be automated. Nevertheless, the geographic information system and the embedded shortest path algorithm proved to be well suited for preliminary corridor location analysis. Future research directions are sketched.
28

Napojení D1 na silniční síť v oblasti Černovické Terasy / Connection of the road network to the D1 motorway in the Černovická Terasa area

Mička, Michal January 2019 (has links)
The aim of the diploma thesis is to propose the connection of a road network on the territory of Černovická Terasa on the D1 motorway - in particular Průmyslová, Tuřanka, Řípská and Šlapanická. This is to find an optimal solution for local, regional and long-distance routes, which primarily enable non-residential use of the site along the D1 motorway. 5 variants of the solution were found in the thesis, 1 variant was elaborated in detail.
29

Dálniční viadukt / Motorway Viaduct

Čtvrtlík, Libor January 2020 (has links)
The aim of diploma thesis was designing motorway viaduct over rowing track. From three possible options was selected one, which represents cable stayed bridge with three spans. Design procedures and assessments were pefrormed to comply with the ultimate an serviceability limit state according to valid European standards. The calculation was performed in software Midas Civil 2020. Structural assessment was done by IDEA Statica 10.1 in combination with hand-done calculation. The part of this thesis is also enclosed drawings and visualizations.
30

Návrh mostu na dálnici D48 / Design of bridge on the motorway D48

Holuša, Adam January 2019 (has links)
Diploma thesis deals with design of a new bridge on motorway D48 located on bypass of Frýdek – Místek. Total spread of the bridge is 113 meters. Thesis includes 3 studies. For next assesment was chosen concrete girder box construction with 3 spans. Bridge is bulit on falsework. Structural analysis includes influences of construction by TDA method. Load effect is solved in Scia Engineer 18.0. The assessment of the bridge was made according to EC.

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