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Functional Properties of Concrete Roads - Development of an Optimisation Model and Studies on Road Lighting Design and Joint PerformanceLöfsjögård, Malin January 2003 (has links)
The roads constitute a major part of the nationsinfrastructure. For the society and the individuals it isimportant with a well functioning road network. To sustain theimpact from traffic intensity and heavy loads durable pavementsare demanded. Concrete pavements for roads with high trafficintensity and heavy loads are common in the USA and in severalEuropean countries. In Sweden, less than 1 % of the roadnetwork consists of concrete roads. The research about concrete road pavements has been focusingon development of design methods and studies of surfaceproperties like friction, longitudinal evenness, wearresistance and noise. To increase the knowledge and use ofconcrete roads there is a need to optimise the differentfunctional properties with regard to each other and to socialfactors. The objective of this doctoral thesis is to survey, analyseand quantify relationships between functional properties ofconcrete roads and social factors such as environmental impact,traffic and user safety, riding comfort and economicconsiderations (costs). The goal is to develop a model that canbe used as an instrument for optimising the concrete roaddesign. This thesis describes a thorough literature investigation,special studies on road lighting design of concrete pavements,laboratory investigations about saw-cutting times for jointsand bonding properties of dowels and development of anoptimisation model. The literature investigation has resultedin compiled knowledge on functional properties of concreteroads and their relationships with social factors. A compiledanalysis has also been performed from follow-ups of the fourconcrete roads constructed in Sweden in the 1990s. From thespecial study on road lighting design, proposals are made forusing new values for brightness and specularity and changingthe classification of wet concrete pavements. Theinvestigations of joint performance have given recommendationsfor the earliest saw-cutting time for joints in concrete roads.An optimisation model is proposed, and presently parts of themodel can be used for economic comparisons between differentalternatives. The proposed model needs further research regardingvaluation of the relationships before the model can be used asa total model. Other areas interesting for further researchare: road lighting design and especially wet pavements, upperbound of sawcutting time for joints and further analysis ofdowel performance.
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Functional Properties of Concrete Roads - Development of an Optimisation Model and Studies on Road Lighting Design and Joint PerformanceLöfsjögård, Malin January 2003 (has links)
<p>The roads constitute a major part of the nationsinfrastructure. For the society and the individuals it isimportant with a well functioning road network. To sustain theimpact from traffic intensity and heavy loads durable pavementsare demanded. Concrete pavements for roads with high trafficintensity and heavy loads are common in the USA and in severalEuropean countries. In Sweden, less than 1 % of the roadnetwork consists of concrete roads.</p><p>The research about concrete road pavements has been focusingon development of design methods and studies of surfaceproperties like friction, longitudinal evenness, wearresistance and noise. To increase the knowledge and use ofconcrete roads there is a need to optimise the differentfunctional properties with regard to each other and to socialfactors.</p><p>The objective of this doctoral thesis is to survey, analyseand quantify relationships between functional properties ofconcrete roads and social factors such as environmental impact,traffic and user safety, riding comfort and economicconsiderations (costs). The goal is to develop a model that canbe used as an instrument for optimising the concrete roaddesign.</p><p>This thesis describes a thorough literature investigation,special studies on road lighting design of concrete pavements,laboratory investigations about saw-cutting times for jointsand bonding properties of dowels and development of anoptimisation model. The literature investigation has resultedin compiled knowledge on functional properties of concreteroads and their relationships with social factors. A compiledanalysis has also been performed from follow-ups of the fourconcrete roads constructed in Sweden in the 1990s. From thespecial study on road lighting design, proposals are made forusing new values for brightness and specularity and changingthe classification of wet concrete pavements. Theinvestigations of joint performance have given recommendationsfor the earliest saw-cutting time for joints in concrete roads.An optimisation model is proposed, and presently parts of themodel can be used for economic comparisons between differentalternatives.</p><p>The proposed model needs further research regardingvaluation of the relationships before the model can be used asa total model. Other areas interesting for further researchare: road lighting design and especially wet pavements, upperbound of sawcutting time for joints and further analysis ofdowel performance.</p>
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Traffic Safety Evaluation of Future Road Lighting SystemsDully, Michael January 2013 (has links)
While new road lighting technologies, either LED or adaptive road lighting systems, offer a wide range of unique potential benefits (mainly in terms of energy savings), it is necessary to evaluate the safety impacts of these technologies on road users. The literature survey shows that providing light on previous unlit roads has a positive effect on traffic safety. Reducing the amount of light has the opposite effect. These studies are usually conducted by using crash numbers, which makes it impossible to draw conclusions on changes in driving behaviour. Driving behaviour analyses need special approaches and indicators. Therefore indirect indicators such as speed and safety relationship, jerky driving and traffic conflict parameters are presented. The individual character of such data is difficult to deal with and limits big scale analyses. In order to have a practical example of such indicators a case study is conducted. Floating car data collected in Vienna is used to analyse travel speeds of taxi drivers at two LED test sites. A simple before-after analysis is used with data from January 2011 to May 2012 in order to examine an expected increase in speed due to a better visual performance of LED light. However the results show either no changes at all or a trend in speed reduction of 1km/h in average. Unfavourable test site locations might limit the significance of the results.
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Zpětný výpočet křivek svítivosti svítidel určených pro osvětlování komunikací / Reverse calculation of the luminous intensity curves of street lighting luminairesKnápková, Dagmar January 2019 (has links)
This master´s thesis deals with the reverse calculation of luminous curves for roads according to ČSN EN 13201. The thesis is divided into the theoretical and the practical part. The theoretical part describes the basic requirements and procedures for calculating the luminous curves. The practical part describes the program, created in the Matlab environment, which is designed for the practical calculation of the ideal luminous curve, for each situation given by the user. Further particular example of the calculation is given.
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Towards a general optimal model for minimizing nighttime road traffic accidents and road lighting power consumptionJun, Ma January 2010 (has links)
<p>Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.</p>
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Towards a general optimal model for minimizing nighttime road traffic accidents and road lighting power consumptionJun, Ma January 2010 (has links)
Nowadays, NRTS (Nighttime Road Traffic Safety) and energy saving are very hot topics in transportation field. This thesis investigates a general optimal model for minimizing NRTAs (nighttime road traffic accidents) and power consumption of the road lighting. To establish this model, the relationship between N/D RTAs (Night to Day Road Traffic Accidents) ratio and road lighting condition and the relationship between power consumption and road lighting condition have been studied and explained. A media variable “economic cost” has been chosen which is used for making a connection between these two relationships. The evaluations of NRTAs and power consumption from cost point of view are introduced as well. The impacts of each internal factor defined by author are explained carefully. The result of the model based on these relationships and internal influencing factors is presented in the paper. Finally, the recommendations for reducing NRTAs and/or power consumption, as well as other interesting areas for further study are presented.
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Koncept moderního LED svítidla pro osvětlení pozemních komunikací / Modern LED luminaire concept for road lightingKrejčí, Miroslav January 2018 (has links)
This thesis deals with design of optical system for road lighting luminaire. In the beginning the basic photometric quantities and assessment methodology for requirements of lighting class M are described. The next step is the programming of algorithm which evaluates the road lighting requirements using few boundary conditions. The input of the algorithm is also luminous intensity (power emitted in a particular direction). By the turning the algorithm over, it is possible to evaluate the luminous intensity from the road lighting requirements. Those luminous intensities are used in the process of modification of optical lens. The ray tracing of modified models of lenses was performed to obtain the tables of luminous intensity. The values of luminous intensity are verified in the same algorithm. Finally, the comparison of results was made including several luminaires out there.
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Hur påverkar en ökad belysningsstyrka på övergångsställen bilisters hastighet? / How an increased illuminance at pedestrian crossing affects the speed of vehicles?Karlsson, Anton, Hjorth, Alexander January 2020 (has links)
Syftet med studien var att undersöka hur en ökad belysningsstyrka på övergångsställen påverkar bilisters hastighet. Vid vissa övergångsställen används idag intensivbelysning. Intensivbelysning innebär att belysningen förstärkts vid platsen och utformas av en eller flera armaturer över eller i anknytning till övergångsställen för att öka synbarheten för fotgängare. Målet med studien är att undersöka om en ökad belysningsstyrka på övergångsställen har en positiv eller en negativ påverkan på bilisters hastighet och därför kunna bidra till en ökad kunskap inom trafiksäkerhet. För att undersöka hur intensivbelysning påverkar bilisters hastighet har hastighetsmätningar utförts på två övergångsställen i centrala Jönköping samt vid en kontrollplats. Hastighetsmätningarna utfördes på en urban väg med en hastighetsbegränsning på 40 km/h. mätningarna utfördes under perioden 2020-03-16 – 2020-03-24. Det ena övergångsstället har intensivbelysning det andra har det inte, för att kunna jämföra de två platserna utfördes mätningar av både luminans och belysningsstyrka. Övergångsstället med intensivbelysning benämnt som observationsplats 1, hade en medelbelysningsstyrka på 73,27 lux och en medelluminans på 2,7 cd/m². Övergångsstället utan intensivbelysning benämnt som observationsplats 2, hade en medelbelysningsstyrka på 15.63 lux och en medelluminans på 1,3 cd/m². Det skiljer alltså 57,64 lux i medelbelysningsstyrka mellan observationsplats 1 och observationsplats 2, och 1,4 cd/m² i medelluminans. Vid observationsplats 1 uppmättes dagtid 10 passager. Vilket resulterade i en medelhastighet på 35,7 km/h (standardavvikelse 4,6 km/h). Kvällstid uppmättes 35 passager. Vilket resulterade i en medelhastighet på 37,49 km/h (standardavvikelse 5,3 km/h). Vid observationsplats 2 uppmättes dagtid 10 passager. Vilket resulterade i en medelhastighet på 40 km/h (standardavvikelse 4 km/h). Kvällstid uppmättes 34 passager. Vilket resulterade i en medelhastighet på 36 km/h (standardavvikelse 4 km/h). Resultatet från studien antyder att intensivbelysning vid övergångsställen leder till en högre fordonshastighet. Skillnaden i medelhastighet mellan observationsplats 1 och observationsplats 2 var låg 1,49 km/h, standardavvikelsen var hög (observationsplats 1 5,3 km/h observationsplats 2 4 km/h).
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