The cost of a road construction over its service life is a function of the design, quality of construction, maintenance strategies and maintenance operations. Unfortunately, designers often neglect a very important aspect which is the possibility to perform future maintenance activities. The focus is mainly on other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This licentiate thesis is a part of a Ph.D. project entitled “Road Design for lower maintenance costs” that aims to examine how the life-cycle costs can be optimized by selection of appropriate geometrical designs for the roads and their components. The result is expected to give a basis for a new method used in the road planning and design process using life-cycle cost analysis with particular emphasis on road maintenance. The project started with a review of literature with the intention to study conditions causing increased needs for road maintenance, the efforts made by the road authorities to satisfy those needs and the improvement potential by consideration of maintenance aspects during planning and design. An investigation was carried out to identify the problems which obstruct due consideration of maintenance aspects during the road planning and design process. This investigation focused mainly on the road planning and design process at the Swedish Road Administration. However, the road planning and design process in Denmark, Finland and Norway were also roughly evaluated to gain a broader knowledge about the research subject. The investigation was carried out in two phases: data collection and data analysis. Data was collected by semi-structured interviews with expert actors involved in planning, design and maintenance and by a review of design-related documents. Data analyses were carried out using a method called “Change Analysis”. This investigation revealed a complex combination of problems which result in inadequate consideration of maintenance aspects. Several urgent needs for changes to eliminate these problems were identified. Another study was carried out to develop a model for calculation of the repair costs for damages of different road barrier types and to analyse how factors such as road type, speed limits, barrier types, barrier placement, type of road section, alignment and seasonal effects affect the barrier damages and the associated repair costs. This study was carried out using a method called the “Case Study Research Method”. Data was collected from 1087 barrier repairs in two regional offices of the Swedish Road Administration, the Central Region and the Western Region. A table was established for both regions containing the repair cost per vehicle kilometre for different combinations of barrier types, road types and speed limits. This table can be used by the designers in the calculation of the life-cycle costs for different road barrier types.

The high percentage of trucks combined with the mountainous terrain along the I-81 corridor in the state of Virginia has resulted in significant capacity reduction and delay increases. Different alternatives are being considered in order to alleviate the capacity impacts of trucks along I-81. These alternatives may include adding lanes along grade sections, reducing grade through a re-alignment of the interstate, considering alternate modes for transporting goods, or even reducing the number of trucks on the interstate during peak periods. The evaluation of these alternative measures requires a sophisticated evaluation tool that not only captures the dynamics of trucks as they travel along grades, but also accurately captures the formation of shockwaves behind these trucks. This project demonstrates the effectiveness of the INTEGRATION model as such an evaluation tool through the modeling of a 30-mile segment of I-81 between Roanoke and Christiansburg. Initial simulation results indicate that trucks experience delays that exceed light vehicle delays by as much as 18%. The results obtained showed that the 100 lb/hp truck was the most economical. The 100 lb/hp truck gave the best average travel time followed by the 200 lb/hp, combined, and 300 lb/hp trucks, which were represented by an increase that ranged from 16% to 63% for the AM peak traffic, and 26% to 120% for the PM peak. There were a total of 8085 vehicles discharged during the AM peak as opposed to the 10060 vehicles that were discharged during the PM peak, a 24% increase over the AM peak. / Master of Science

The cost of a road construction over its service life is a function of the design, quality of construction, maintenance strategies and maintenance operations. Unfortunately, designers often neglect a very important aspect which is the possibility to perform future maintenance activities. The focus is mainly on other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This licentiate thesis is a part of a Ph.D. project entitled “Road Design for lower maintenance costs” that aims to examine how the life-cycle costs can be optimized by selection of appropriate geometrical designs for the roads and their components. The result is expected to give a basis for a new method used in the road planning and design process using life-cycle cost analysis with particular emphasis on road maintenance. The project started with a review of literature with the intention to study conditions causing increased needs for road maintenance, the efforts made by the road authorities to satisfy those needs and the improvement potential by consideration of maintenance aspects during planning and design. An investigation was carried out to identify the problems which obstruct due consideration of maintenance aspects during the road planning and design process. This investigation focused mainly on the road planning and design process at the Swedish Road Administration. However, the road planning and design process in Denmark, Finland and Norway were also roughly evaluated to gain a broader knowledge about the research subject. The investigation was carried out in two phases: data collection and data analysis. Data was collected by semi-structured interviews with expert actors involved in planning, design and maintenance and by a review of design-related documents. Data analyses were carried out using a method called “Change Analysis”. This investigation revealed a complex combination of problems which result in inadequate consideration of maintenance aspects. Several urgent needs for changes to eliminate these problems were identified. Another study was carried out to develop a model for calculation of the repair costs for damages of different road barrier types and to analyse how factors such as road type, speed limits, barrier types, barrier placement, type of road section, alignment and seasonal effects affect the barrier damages and the associated repair costs. This study was carried out using a method called the “Case Study Research Method”. Data was collected from 1087 barrier repairs in two regional offices of the Swedish Road Administration, the Central Region and the Western Region. A table was established for both regions containing the repair cost per vehicle kilometre for different combinations of barrier types, road types and speed limits. This table can be used by the designers in the calculation of the life-cycle costs for different road barrier types. / QC 20101112

Asset managers continue to prepare physical infrastructure investments needed to accommodate the emerging technologies, namely vehicle connectivity, electrification, and automation. The provision of new infrastructure and modification of existing infrastructure is expected to incur a significant amount of capital investment. Secondly, with increasing EV and CAV operations, the revenues typically earned from vehicle registrations and fuel tax are expected to change due to changing demand for vehicle ownership and amount of travel, respectively. This research estimated (i) the changes in highway expenditures in an era of ECAV operations, (ii) the net change in highway revenues that can be expected to arise from ECAV operations, and (iii) the changes in user equity across the highway user groups (vehicle classes). In assessing the changes in highway expenditures, the research developed a model to predict the cost of highway infrastructure stewardship based on current and/ or future system usage. <div><br></div><div>The results of the research reveal that CAVs are expected to significantly change the travel patterns, leading to increased system usage which in turn results in increased wear and tear on highway infrastructure. This, with the need for new infrastructure to support and accommodate the new technologies is expected to result in increased highway expenditure. At the same time, CAVs are expected to have significantly improved fuel economy as compared to their human driven counterparts, leading to a decrease in fuel consumption per vehicle, resulting in reduced fuel revenues. Furthermore, the prominence of EVs is expected to exacerbate this problem. This thesis proposed a revision to the current user fee structure to address these impacts. This revision contains two major parts designed to address the system efficiency and equity in the near and long term. For the near term, this thesis recommended a variable tax scheme under which each vehicle class pays a different fuel tax rate. This ensures that both equity and system efficiency are improved during the transition to ECAV. In the long term, this thesis recommended supplementing the fuel tax with a distance based VMT tax, applicable to electric vehicles.<br></div>

Developments in high resolution traffic sensors over the past decades are providing a wealth of empirical speed-flow data. Travel demand models use speed-flow relationships to assign traffic flows to network links. However, speed-flow relationships have not been revalidated against new detailed traffic sensor data. Therefore, it is necessary to revisit speed-flow relationships based on actual measured conditions on network links rather than assuming constant speed-flow relationships over entire highway network systems. Speed-flow relationships have been particularly difficult to calibrate and estimate when traffic volumes approach capacity, i.e. when the v/c ratio approaches one. This thesis empirically evaluates the speed-flow relationships for v/c < 1 using field data. For congested conditions (v/c > 1) a theoretical approach is taken. A new methodology to determine the distribution of the activation of bottlenecks, bottleneck duration, and bottleneck deactivation is proposed. This thesis is a new contribution to understand the stochastic nature of freeway capacity as well as bottleneck duration, activation, and deactivation. Unlike previous research efforts, this thesis studies speed-flow relationships at the lane level and later presents a method to estimate speed-flow relationships at the link level.

Many cities including Stockholm gave highways as a solution to traffic congestion. Essingeleden motorway is part of European route E4 and today is the busiest road in Sweden. It connects the north and the south part of the country, by crossing islands of central Stockholm. The result of that is a huge swath through the city, that splits the island of Kungsholmen into two pieces, creating isolated neighbourhoods and huge traffic jams. I believe that Essingeleden is reaching its end as a highway, especially since Stockholm is preparing to become a fossil fuel-free city until 2050. Last, the Stockholm bypass project will be able to replace Essingeleden outside the city centre, therefore the Essingeleden worth is being called into question.  Through my diploma project I will propose the transformation of Essingeleden motorway into surface streets, boulevards and parks to improve the accessibility and the street network. Furthermore, my solution will connect the isolated neighbourhoods by healing the local street networks and improve the regional traffic dispersion. Last, since Essingeleden highway is a very strong and central network, parts of the infrastructure will remain and will accommodate a new public transportation route to replace the highway network.

Experimental investigations have been conducted in the VPI & SU towing basin to assess the feasibility of testing fully submerged configurations, simulating aerodynamic phenomena, and in particular, measuring aerodynamic interference force between blunt bodies. Special instrumented struts were constructed and calibrated for the measurement of drag and side forces. A series of tests were conducted with spherical models in order to verify the reliability of the method by comparison with earlier classical results. The effects of flat walls and surface wave formation were studied and it was discovered that their influence on aerodynamic forces is reduced to less than 10% if the body is removed from the wall or the surface by a distance larger than half its typical width. Experiments were also conducted with crude models that approximate the shapes of a passenger car and a truck. In particular, the passing process under the presence of a strong wind was simulated by towing the models at an angle of 240 with respect to motion of the carriage. The results appear to be essentially in agreement with the data received with much larger models tested in air, by other investigators. / Master of Science

No description available.

No description available.

No description available.