Night time construction has adopted as a preferred method of scheduling to alleviate the problems caused by road works during the day. Over the past few years, night-time construction has been increased; it will inevitably continue to grow. Continued increase in the volume of roadwork done at night has resulted from a combination of road deterioration and traffic congestion. Although nighttime road construction is seen as the solution to alleviate the problems associated with day-time repairs and congestion, it has its own challenges and problems. Cost, productivity, quality, noise and human factors are some of the few factors that night-time road construction brings. This study is aimed at understanding the factors that influence the productivity of night-time construction and proposing strategies to improve productivity in the South African context. It is commonly known that quality and productivity differs from one roadwork site to another during night-time road construction. Some roadwork sites can perform well while others are worse off. However, through literature, the factors categorised as human, management and external may influence the productivity regardless of the operation. The current study investigates the influence of these factors on the productivity of work done at night through structured questionnaire. The results of the study show that there is minimal if no effect on the productivity of work done at night. Human factors that influence the performance of the labour have no impact on productivity, whereas management and external factors have minimal impact on the productivity of night-time road construction projects.

Thesis advisor: Rudolph Hon / The application of road de-icers has lead to increasing solute concentrations in surface and ground water across the northern US, Canada, and northern Europe. In a public water supply well field in southeastern Massachusetts, USA, chloride concentrations in ground water from an unconfined aquifer have steadily risen for the past twenty years. The objectives of this study are to understand spatial and temporal trends in road salt concentrations in order to identify contamination sources and fate. To this end, the methods of this project include field and lab work. Water samples were collected from surface, near-surface, and ground water from March 2012 to March 2013. The other major field data are specific conductance measurements from probes located in three piezometers. In the lab, all samples were analyzed for major ions with ion chromatography analysis. Additionally, trace elements were measured by inductively coupled plasma analysis on a subset of samples. The results of these hydrogeochemical procedures showed several important trends. First, the highest concentrations of sodium and chloride from near-surface samples were located near to roadways. Second, ground water samples taken from glacial sediments contained relatively high concentrations throughout the water column, whereas ground water samples from wetlands had high concentrations only near the surface. Third, there was no clear relationship between pH and cation concentrations. Finally, specific conductance data showed strong seasonal trends near to the surface, whereas values taken from deeper in the aquifer were steadily increasing. Based on these results, it is highly probable that road salt application is the dominate contamination source. The pathways of road salt in the watershed include runoff into surface water and infiltration into the vadose zone and ground water. Road salt appears to preferentially travel through glacial features rather than floodplain features. It is possible that sodium from road salt is sorbed to aquifer sediment and displaces other cations. However, the low values of trace metals suggest that cation exchange is not mobilizing heavy metals. Finally, the increasing specific conductance values deep in the aquifer suggest that road salt is retained within the aquifer and concentrations will likely increase in the future if the current road salt application procedures are continued. / Thesis (MS) — Boston College, 2013. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.

Este trabalho mostra que o uso do palete nas operações de transporte rodoviário de cargas embaladas aumenta o número de viagens com um mesmo veículo nos intervalos de tempo, e possibilita novas variáveis operacionais que, em função da distância de transporte podem fornecer informações para estudos e decisões sobre adotar, ou não, o palete nas empresas. O procedimento adotado foi comparar custos provenientes de operação de transporte com e sem, o uso do palete, usando dados obtidos de pesquisa em campo. As conclusões foram que, ao comparar o palete com o transporte de produtos acabados, as relações entre as consequências de uso do palete nos custos, a disponibilidade de veículos e a receita sobre o custo marginal são dependentes da distância de transporte e são mais significativas para os menores percursos. / This is an attempt to show that the use of pallets in packed road cargo operation increases the number of trips of a single vehicle and it also identifies new variables that could be sent like information to research and to decide work with pallets, depending on transportation distance. The studies are conducted based on field data, through the comparisons of operations with and without pallets. The conclusions are: there are relationships between using the pallet and the vehicle availability and marginal costs. They depend on transportation distance: the shorter the trip the better the operation conditions.

Este trabalho mostra que o uso do palete nas operações de transporte rodoviário de cargas embaladas aumenta o número de viagens com um mesmo veículo nos intervalos de tempo, e possibilita novas variáveis operacionais que, em função da distância de transporte podem fornecer informações para estudos e decisões sobre adotar, ou não, o palete nas empresas. O procedimento adotado foi comparar custos provenientes de operação de transporte com e sem, o uso do palete, usando dados obtidos de pesquisa em campo. As conclusões foram que, ao comparar o palete com o transporte de produtos acabados, as relações entre as consequências de uso do palete nos custos, a disponibilidade de veículos e a receita sobre o custo marginal são dependentes da distância de transporte e são mais significativas para os menores percursos. / This is an attempt to show that the use of pallets in packed road cargo operation increases the number of trips of a single vehicle and it also identifies new variables that could be sent like information to research and to decide work with pallets, depending on transportation distance. The studies are conducted based on field data, through the comparisons of operations with and without pallets. The conclusions are: there are relationships between using the pallet and the vehicle availability and marginal costs. They depend on transportation distance: the shorter the trip the better the operation conditions.

No description available.

Road salt and other products used for winter maintenance in the Northeastern United States and Canada can impact ecosystems, pose risks to aquatic life, and create human health concerns. In response to these impacts and rising cost of materials, many municipalities have adopted preventative best management practices (BMPs) that reduce the amount of application materials used, save money, and/or provide a similar level of service and safety. Private companies that maintain parking lots and private roadways also contribute to the increasing chloride concentrations seen in the northeastern United States and Canada, but the practices of these companies have largely not been previously assessed. This mixed-methods study focused on private contractors in the Lake Champlain Basin in Vermont and New York who maintain parking lots, driveways, and roadways. A census and interviews were used to characterize practices used by private contractors and to identify key factors that drive their decision-making processes. A literature review was conducted to understand winter maintenance practices including recommended BMPs, potential environmental impacts and ways that contractors may be incentivized to adopt reduced-salt practices. The literature review informed the development of a census of winter maintenance companies in the Lake Champlain Basin. Contractors most often reported maintaining parking lots and roadways, and most commonly applying sand and salt. Physical snow removal techniques and adjustable material application rates were commonly adopted BMPs. Other BMPs including proactive applications, calibrating equipment, and using brine were infrequently adopted. In addition, the study examined the motivations and barriers contractors have to adopt recommended BMPs through qualitative and quantitative methods. Commonly reported motivations included perceived liability or safety concerns, customer request or expectations, and cost. Commonly reported barriers included cost, time, and customer requests or expectations. Across census and interview results, companies that focus on commercial lots and individuals who learn management practices through in-person trainings or online resources were found to use more recommended BMPs than other groups. Results of the study informed the development of outreach recommendations to increase private contractors’ adoption of BMPs and to lessen road salt use. These included: developing online resources, annual conferences, and reoccurring in-person trainings.

For operational and planning purposes it is important to observe, predict and monitor the traffic performance of congested urban road links and networks. This monitoring effort describes the traffic conditions in road networks using congestion performance measures. The objective of this research is to analyse and evaluate methods for measuring congestion and congestion performance measures for monitoring purposes. For this objective, a selection of the required aspects of the performance measures in the literature is considered. The aspects to be considered can be classified into two categories: A first group relates to the statistical aspects of these indicators, i.e. reliability. The second relates to their ability to capture the impacts of congestion, i.e .relevance. The reliability and relevance of the congestion performance measures are evaluated. A recommendation of the most suitable indicator is provided at the end of the study. / QC 20110912

No description available.

The recession of the early 1990’s marked the starting point for a transformation of the Swedish transportation industry. Cost oriented production techniques by the industry’s customer increased demand on swiftness, reliability and flexibility in transportation services. This development has continued ever since which in turn has continuously increased the rates of harmful discharges of emissions. The research is performed on the Swedish plastic industry and examines the relationship between environmental sustainability, lead time and cost when selecting road carrier for transportations. The main purpose is to examine to what extent environmental concerns are taken into account when deciding over distribution and furthermore, whether there exist potential and ambitions for improvements. Out of theories concerning transportation modal choice, four points of interest constitutes the basis for the empirical gathering; prioritization of selection determinants, environmental requirements in procurement of transportation services, use of rail freight and acceptable cost levels for implementing environmental sustainability. The study shows that the market of the Swedish plastic industry is driven by price competition and constant pressure from international trade. Naturally, cost is considered to be the foremost selection determinant in terms of transportation modal choice, followed by reliability and lead time. Furthermore, the study shows that environment is of low priority in respect to the other selection determinants. Although the current market condition diminishes the possibilities for changes, there exists a general ambition to become more environmental within the distribution activities. A majority of the respondent firms could potentially accept levels of increased transportation costs which balance with the costs of guaranteeing environmental sustainability in road transportations. In reference to increased environmental ambitions, three conclusions can be drawn. The relationship between environmental sustainability, lead time and cost allow for environmental improvements if lead time can be extended to the maximum conceivable limit of the market. Furthermore, the price competition of the market makes own initiatives impossible in terms of raising price for transportations; environmental sustainability in road transportation must therefore be preceded by demand for such. Finally, it can be concluded that environmental improvements cannot be achieved single handedly; costs must be evenly distributed among the suppliers, customers and haulers.

The focus of this project is highway construction zones and the impact of lane closures on traffic. By measuring throughput (the number of vehicles that can flow through a work zone in a given amount of time), analysis was performed to determine the factors that affect this value. Successful data collection uncovered a paradox. Often work zones would see no queuing, indicating the lane could have been closed for longer hours. Alternatively sites with forced flow allowed fewer vehicles through the site than expected, indicating that the design value is too high, requiring shorter lane closure hours. A generic model for throughput was developed as well as a better functioning highway specific model. In addition to these models, this project developed a spreadsheet-based form of analysis named SZUDA (Simplified work Zone User Delay Analysis) that determines queue length and approximate costs associated with road user delay.