• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 12
  • 6
  • 4
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 54
  • 54
  • 18
  • 13
  • 10
  • 10
  • 8
  • 8
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 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.
11

Traffic performance on two-lane, two-way highways examination of new analytical approaches /

Durbin, Casey Thomas. January 2006 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: Ahmed Al-Kaisy. Includes bibliographical references (leaves 116-118).
12

Fatal crash trends and analysis in southeastern states

Wang, Chunyan. January 2006 (has links)
Thesis (Ph. D.)--Georgia Institute of Technology, 2006. / Includes bibliographical references (p. 209-211). Also available online via the Georgia Institute of Technology ETD website (http://etd.gatech.edu/).
13

Black Spots: Roads and Risk in Rural Kenya

Melnick, Amiel Bize January 2018 (has links)
This dissertation examines “post-agrarian” transformations in Kenyan rural areas. But where rural transformation is usually written as a story about land, Black Spots is a story about roads. Kenya’s massive investment in roads infrastructure over the last decade has intersected with the decline in smallholder agriculture in such a way that, for many rural residents, fortunes are now imagined on the road rather than on the land. Roadside trade, transport, and even salvage from crashes provide supplementary livings for rural populations facing declining agricultural opportunities. The dissertation argues that in the context of austerity policies and rural abandonment, road work and its “fast money” not only expose roadside residents to physical danger, but also entrench entrepreneurial risk ideology into local imaginaries. With the road accident as a lens illuminating a wider landscape of rural hazard, the dissertation shows how rural residents refashion relationships to land, work, technology, and loss in high-risk environments. At the same time, it demonstrates the limits of “risk”—that is, a calculated engagement with potential loss, conducted in the interest of profit—as a framework for managing contingency. In this sense, Black Spots is both an ethnography of risk and of what risk fails to capture. It tracks how rural residents learn to engage bodily and economic hazard and to understand it as risk; how they coordinate the disparate temporalities and technologies of life on the road and life on the land; and how they withstand loss when these attempts do not go as planned. The dissertation thus advances two parallel concerns: on the one hand, it demonstrates how economic practice is at once bodily and reasoned. On the other, it considers how experiences of and ideas about contingency are shaped in relation to shifting economic, social, and infrastructural possibilities.
14

Incorporating Safety into Rural Highway Design

Koorey, Glen January 2009 (has links)
The objectives of this research were to explore ways to assess the safety performance of (predominantly two-lane) rural highways in New Zealand (NZ) and in particular identify driver/road/environmental factors affecting crashes on rural curves. Following a wide-ranging literature review, the Interactive Highway Safety Design Model (IHSDM) was identified as worthy of further investigation for adaptation to use in NZ. To help with this investigation, a comprehensive database was developed of road, traffic, crash and environmental data for all NZ State Highways, divided into variable-length road elements. A number of tasks were identified and undertaken to adapt IHSDM for general use here, including calibrating the Crash Prediction Module (CPM), developing a Design Policy file based on local agency standards, and developing an importing routine for NZ highway geometry and crash data. To assess the effectiveness of IHSDM for predicting the relative safety of rural road alignments, a series of tests were undertaken to confirm its appropriateness for use in NZ. These included “before and after” design consistency checks of a bridge replacement, a “before and after” crash comparison of a major highway realignment, and checks of actual versus predicted crash numbers along longer lengths of highway in varying terrain. These initial investigations have shown that IHSDM is a promising tool for safety and operational assessment of highway alignments (both existing and proposed) in NZ. Incorporating crash history data generally improves IHSDM’s accuracy in crash numbers, and appears to provide a better level of “local calibration” than by using sub-national (e.g. regional or terrain-specific) calibration parameters. Reported fatal/injury crash data generally provide more robust and precise measures than non-injury crashes. Correct specification of the extreme attributes of sub-standard elements (e.g. minimum radius, maximum roadside hazard) appears to be crucial to getting suitably accurate crash estimates on existing alignments. However, IHSDM’s current lack of consideration for bridges and inconsistent adjacent elements are notable omissions that limit the ability of the CPM to assess sub-standard existing routes with as much accuracy as well-designed newer alignments.
15

Integration of GIS into pavement management systems for low volume country roads

Grass, David Michael January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 121-124)
16

Guidelines for determining the most economical roadway surface type for local rural roads

Patel, Himanshu S. January 1900 (has links)
Master of Science / Civil Engineering / Sunanda Dissanayake / The percentage of gravel roads in rural areas in Kansas is higher than most states. A wide variation of traffic volumes across different regions and variations of local conditions and scenarios present a great challenge for local agencies to determine suitable roadway surface types for local rural roads, especially considering constraints on transportation budgets. The primary objective of this research was developing specific guidelines to identify the most suitable roadway surface for a particular roadway section with given conditions. Surveys were carried out to determine the importance of factors affecting the selection of a roadway surface type, where were later used for guideline development. General guidelines were developed using the multi-criteria assessment method in order to fulfill the main objective. The main important factors in decision-making were identified as agency cost, safety, Vehicle Operating Cost (VOC), traffic volume, purpose of road usage, and public preference. Multi-criteria assessment method involves calculating the weights for the factors important in decision-making, the respective scaled values for each factor for paved surface and gravel surface, and eventually calculating the final score for paved and gravel surface type. Equations were formulated to carry out life cycle cost (LCC) analysis along with the present worth evaluation. The formulas provided flexibility to calculate agency cost by considering local variation. VOC was calculated for paved and gravel roads considering variations in speed of different classes of vehicles, gradient and horizontal curve of the road, and the conversion factor for cost on paved surface versus gravel surface. Safety analysis was carried out for local rural roads in Kansas for five years, from 2010 to 2014, using the Kansas Department of Transportation’s KCARS database. After calculating the EPDO crash rates on paved and gravel roads in Kansas, results showed that paved surfaces were in general safer than gravel surfaces, which was taken into consideration while calculating the scaled values for safety. The final score was calculated by multiplying the weights of each factor and their respective scaled values. Roadway surface type with higher score is the preferred alternative for a road section under consideration. A computer-based program was created as a user interface, using Visual Studio, to carry out all complex calculations for determining LCC and VOC considering local variations. The program also helped determine final total scores for paved and gravel roads by considering scaled values of all-important factors considered for conversion. Another approach using cost versus traffic volume showed that the break-even point for traffic volume decreased with an increased percentage of trucks and increased vehicle speeds. Thus, the developed guideline helps determine the best roadway surface type for any set of local conditions.
17

Rural road quality, farm efficiency and income in Ethiopia. Development working papers series 3. Working paper No. 01/15

Wondemu, Kifle Asfaw 06 1900 (has links)
yes / Small scale farmers in Ethiopia are already operating on their land frontier and the scope for an increase in production and rural income should come, among others, through improvement in technical and allocative efficiency. Although the stake of efficiency improvement is substantial, a number of empirical studies undertaken to identify the determinants of efficiency however are few. Moreover, although road infrastructure is among key public goods that significantly influences the farm level economic efficiency, empirical studies that have considered its role in farm efficiency analysis is scarce. This research investigated the link between the quality of rural road and farm level allocative and technical efficiency as well as the impact of inefficiency on farm income. The result showed that households that have all weather road access are 16% technically and two times allocatively more efficient. Both allocative and technical inefficiencies reduce income; the adverse impact of technical inefficiency on income however is stronger. Although household specific factors have contributed to the observed inefficiencyin most cases it is exogenously driven, namely, it is a rational response to market imperfection and risks. Interventions that reduce market and production risks will increase crop output and farm income.
18

Reducing log truck transfer of mud to public roads

Keesee, James M. 12 March 2009 (has links)
The objective of this research was to design and test devices for addition to log trucks that removed mud from the dual-tires before the trucks entered the public road. The four devices built were simple, inexpensive, and could be built by a logging or trucking contractor. The "bar and scraper" and "mud flap" removed 85% and 84% of the mud, respectively, that adhered to the dual-tires during the test. The "bar" and "rope" removed 78% and 40% of the mud, respectively. / Master of Science
19

Influence of limited access roads on Roosevelt elk in the Oregon Coast Range

Cole, Eric K. 07 March 1996 (has links)
No studies have evaluated the effects of limited vehicle access on movements, survival and habitat use of Roosevelt elk (Cervus elaphus roosevelti) . We installed twenty gates, restricting motorized vehicle access by the public in seven discrete Road Management Areas (RMAs), comprising 35% of the study area. We radio-tracked 31 cow elk for 13 months in a 38,000 ha area of the Oregon Coast Range. Prior to the installation of the gates, 20 of these elk had been tracked for 14 months, allowing a paired comparison of elk movements and habitat use before and during the limited access period. The percentage of elk home ranges or core areas within the RMAs did not differ between periods, but there was a clear decrease in daily movement of elk during the limited access period. Survival rates increased during the limited access period and declined after the removal of the gates. During the limited access period, there was a significant increase in the use of open, foraging habitats and areas <150 m from roads. We conducted habitat selection analysis on vegetative cover types, distance from roads and distance from water. In general elk use of vegetative cover types was not significantly different from availability (p<0.05). Elk avoided areas <150 m from roads and selected areas >150 m from roads. Elk selected areas <150 m from streams and avoided areas >600 m from streams. Roosevelt elk should benefit from the preferred alternative of the President's forest Plan, which maintains roadless areas near streams. / Graduation date: 1996
20

Geomorphic considerations in the deterioration of rural roads : the case of Inkandla, Indwedwe and Ga-Modjadji.

Khandlhela, Nkhensani. January 2003 (has links)
The condition of the rural road network in South Africa is in a severe state of deterioration and remains a matter of concern for inhabitants of rural areas. Apart from heavy use, the main problem is that road development is often neglected and the main focus is placed on the geomorphic environment. The objective of this study is to identify the nature of the geomorphic constraints of vehicular access on unarmoured roads in the rural areas of KwaZulu Natal and the Limpopo Province of South Africa, and to gain a better understanding of how these function. It is hoped that some of the insights gained can then be used to inform policy decisions regarding the location and design of rural roads in the future. In this study, a number of unarmoured roads were studied in detail to identify the possible environmental constraints on vehicular access. A number of soil physical and chemical properties were used to examine the state of road degradation. These properties included particle size analysis, soil strength, Cation Exchangeable Capacity and Exchangeable Sodium Percentage. The results of the investigation of soil properties have shown that they play a significant role in road degradation. The major geomorphic factors involved in road deterioration include soil type, soil erosion and precipitation characteristics, mass movements, slope conditions and human activity. The physical characteristics, especially the soil and slope conditions, make the access roads in all study areas susceptible to soil loss. Factors such as geology, drainage and friable soils vulnerable to mass movements have been identified as seriously constraining vehicular access. Soil erosion problems in the study area are largely the result of physical and chemical properties of soils combined with steep gradients and have been identified as the primary cause of road degradation. It was further found that the socio-economic conditions, together with the anthropogenic influences such as the construction of rural access roads on vulnerable slopes, population density and the removal of vegetation cover in all the study areas have significantly enhanced road deterioration. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2003.

Page generated in 0.1747 seconds