873 resultados para Private roads.


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The present world energy production is heavily relying on the combustion of solid fuels like coals, peat, biomass, municipal solid waste, whereas the share of renewable fuels is anticipated to increase in the future to mitigate climate change. In Finland, peat and wood are widely used for energy production. In any case, the combustion of solid fuels results in generation of several types of thermal conversion residues, such as bottom ash, fly ash, and boiler slag. The predominant residue type is determined by the incineration technology applied, while its composition is primarily relevant to the composition of fuels combusted. An extensive research has been conducted on technical suitability of ash for multiple recycling methods. Most of attention was drawn to the recycling of the coal combustion residues, as coal is the primary solid fuel consumed globally. The recycling methods of coal residues include utilization in a cement industry, in concrete manufacturing, and mine backfilling, to name few. Biomass combustion residues were also studied to some extent with forest fertilization, road construction, and road stabilization being the predominant utilization options. Lastly, residues form municipal solid waste incineration attracted more attention recently following the growing number of waste incineration plants globally. The recycling methods of waste incineration residues are the most limited due to its hazardous nature and varying composition, and include, among others, landfill construction, road construction, mine backfilling. In the study, environmental and economic aspects of multiple recycling options of thermal conversion residues generated within a case-study area were studied. The case-study area was South-East Finland. The environmental analysis was performed using an internationally recognized methodology — life cycle assessment. Economic assessment was conducted applying a widely used methodology — cost-benefit analysis. Finally, the results of the analyses were combined to enable easier comparison of the recycling methods. The recycling methods included the use of ash in forest fertilization, road construction, road stabilization, and landfill construction. Ash landfilling was set as a baseline scenario. Quantitative data about the amounts of ash generated and its composition was obtained from companies, their environmental reports, technical reports and other previously published literature. Overall, the amount of ash in the case-study area was 101 700 t. However, the data about 58 400 t of fly ash and 35 100 t of bottom ash and boiler slag were included in the study due to lack of data about leaching of heavy metals in some cases. The recycling methods were modelled according to the scientific studies published previously. Overall, the results of the study indicated that ash utilization for fertilization and neutralization of 17 600 ha of forest was the most economically beneficial method, which resulted in the net present value increase by 58% compared to ash landfilling. Regarding the environmental impact, the use of ash in the construction of 11 km of roads was the most attractive method with decreased environmental impact of 13% compared to ash landfilling. The least preferred method was the use of ash for landfill construction since it only enabled 11% increase of net present value, while inducing additional 1% of negative impact on the environment. Therefore, a following recycling route was proposed in the study. Where possible and legally acceptable, recycle fly and bottom ash for forest fertilization, which has strictest requirements out of all studied methods. If the quality of fly ash is not suitable for forest fertilization, then it should be utilized, first, in paved road construction, second, in road stabilization. Bottom ash not suitable for forest fertilization, as well as boiler slag, should be used in landfill construction. Landfilling should only be practiced when recycling by either of the methods is not possible due to legal requirements or there is not enough demand on the market. Current demand on ash and possible changes in the future were assessed in the study. Currently, the area of forest fertilized in the case-study are is only 451 ha, whereas about 17 600 ha of forest could be fertilized with ash generated in the region. Provided that the average forest fertilizing values in Finland are higher and the area treated with fellings is about 40 000 ha, the amount of ash utilized in forest fertilization could be increased. Regarding road construction, no new projects launched by the Center of Economic Development, Transport and the Environment in the case-study area were identified. A potential application can be found in the construction of private roads. However, no centralized data about such projects is available. The use of ash in stabilization of forest roads is not expected to increased in the future with a current downwards trend in the length of forest roads built. Finally, the use of ash in landfill construction is not a promising option due to the reducing number of landfills in operation in Finland.

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Texas Department of Transportation, Austin

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In, The law library, Philadelphia, 1834, v.4, Apr-Jun.

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Much of the nation's rural road system is deteriorating. Many of the roads were built in the 1880s and 1890s with the most recent upgrading done in the 1940s and 1950s. Consequently, many roads and bridges do not have the capacity for the increased loads, speed, and frequent use of today's vehicles. Because of the growing demands and a dense county road system (inherited from the land settlement policies two centuries ago), revenue available to counties is inadequate to upgrade andmaintain the present system. Either revenue must be increased - an unpopular option - or costs must be reduced. To examine cost-saving options, Iowa State University conducted a study of roads and bridges in three 100 square mile areas in Iowa: • A suburban area • A rural area with a large number of paved roads, few bridges, and a high agricultural tax base and •A more rural area in a hilly terrain with many bridges and gravel roads, and a low agricultural tax base. A cost-benefit analysis was made on the present road system in these areas on such options as abandoning roads with limited use, converting some to private drives, and reducing maintenance on these types of roads. In only a few instances does abandonment of low traffic volume roads produce cost savings for counties and abutting land owners that exceed the additional travel costs to the public. In this study, the types of roads that produced net savings when abandoned were: • A small percentage (less than 5 percent) of the nonpaved county roads in the suburban area. However, net savings were very small. Cost savings from reducing the county road system in urbanized areas are very limited. • Slightly more than 5 percent of the nonpaved county roads in the most rural area that had a small number of paved county roads. • More than 12 percent of the nonpaved roads in the rural area that had a relatively large number of paved county and state roads. Converting low-volume roads to low-maintenance or Service B roads produces the largest savings of all solutions considered. However, future bridge deterioration and county liability on Service B roads are potential problems. Converting low-volume roads to private drives also produces large net savings. Abandonment of deadend roads results in greater net savings than continuous roads. However, this strategy shifts part of the public maintenance burden to land owners. Land owners also then become responsible for accident liability. Reconstruction to bring selected bridges with weight restrictions up to legal load limits reduces large truck and tractor-wagon mileage and costs. However, the reconstruction costs exceeded the reduction in travel costs. Major sources of vehicle miles on county roads are automobiles used for household purposes and pickup truck travel for farm purposes. Farm-related travel represents a relatively small percent of total travel miles, but a relatively high percentage of total travel costs.

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Includes bibliography

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Análisis de los sistemas de mitigación del riesgo de tráfico en autopistas de peaje en diferentes países de Latinoamérica. This paper presents a cross-country analysis of traffic risk allocation in road concessions of Latin America. It shows that some countries such as Chile, Colombia, and Peru have been greatly concerned with mitigating traffic risk, either by putting into practice public guarantees, implementing flexible term concessions, or through availability payment concessions; whereas other countries such as Mexico and Brazil have assigned traffic risk to the private concessionaire by using fixed-term concession contracts without any traffic guarantees. Based on an analysis of data from 1990 to 2010, the paper finds that shifting traffic risk from the concessionaire to the government or users was not confined to the riskiest projects, as one might expect. The analysis also suggests that the implementation of traffic risk mitigation mechanisms in Latin American toll roads has not been very successful in reducing renegotiation rates or in increasing the number of bidders in the tenders

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This paper describes a theoretical model based primarily on transaction costs, for comparing the various tendering mechanisms used for transportation Public-Private Partnership (PPP) projects. In particular, the model contrasts negotiated procedures with the open procedure, as defined by the current European Union legislation on public tendering. The model includes both ex ante transaction costs (borne during the tendering stage) and ex post transaction costs (such as enforcement costs, re-negotiation costs, and costs arising from litigation between partners), explaining the trade-off between them. Generally speaking, it is assumed that the open procedure implies lower transaction costs ex ante, while the negotiated procedure reduces the probability of the appearance of new contingencies not foreseen in the contract, hence diminishing the expected value of transaction costs ex post. Therefore, the balance between ex ante and ex post transaction costs is the main criterion for deciding whether the open or negotiated procedure would be optimal. Notwithstanding, empirical evidence currently exists only on ex ante transaction costs in transportation infrastructure projects. This evidence has shown a relevant difference between the two procedures as far as ex ante costs are concerned, favouring the open procedure. The model developed in this paper also demonstrates that a larger degree of complexity in a contract does not unequivocally favour the use of a negotiated procedure. Only in those cases dealing with very innovative projects, where important dimensions of the quality of the asset or service are not verifiable, may we observe an advantage in favour of the negotiated procedure. The bottom line is that we find it difficult to justify the employment of negotiated procedures in most transportation PPP contracts, especially in the field of roads. Nevertheless, the field remains open for future empirical work and research on the levels of transaction costs borne ex post in PPP contracts, as well as on the probabilities of such costs appearing under any of the procurement procedures.

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A branch road. -- Up the coolly. -- Among the cornrows. -- The return of a private. -- Under the lion's paw. -- The creamery man. -- A day's pleasure. -- Mrs. Ripley's trip. -- Uncle Ethan Ripley. -- God's ravens. -- A "good fellow's" wife.

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Introduction.--A branch road.--Up the Coolly.--Among the corn-rows.--The return of a private.--Under the lion's paw.--The creamery man.--A day's pleasure.--Mrs. Ripley's trip.--Uncle Ethan Ripley.

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"July 1937."

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Approval of the Clean Development Mechanism, provided for in the Kyoto Protocol, enables countries with afforested land to trade in carbon emissions reduction certificates related to carbon dioxide equivalent quantities (CO(2-e)) stored within a certain forest area. Potential CO(2-e) above base line sequestration was determined for two forest sites on commercial eucalyptus plantations in northern Brazil (Bahia). Compensation values for silvicultural regimes involving rotation lengths greater than economically optimal were computed using the Faustmann formula. Mean values obtained were US$8.16 (MgCO(2-e))(-1) and US $7.19 (MgCO(2-e))(-1) for average and high site indexes, respectively. Results show that carbon supply is more cost-efficient in highly productive sites. Annuities of US$18.8 Mg C(-1) and US$35.1 Mg C(-1) and yearly payments of US$4.4 m(-3) and US$8.2 m(-3) due for each marginal cubic meter produced were computed for high and average sites, respectively. The estimated value of the tonne of carbon defines minimum values to be paid to forest owners, in order to induce a change in silvicultural management regimes. A reduction of carbon supply could be expected as a result of an increase in wood prices, although it would not respond in a regular manner. For both sites, price elasticity of supply was found to be inelastic and increased as rotation length moved further away from economically optimal: 0.24 and 0.27 for age 11 years in average- and high-productivity sites, respectively. This would be due to biomass production potential as a limiting factor; beyond a certain threshold value. an increase in price does not sustain a proportional change in carbon storage supply. The environmental service valuation model proposed might be adequate for assessing potential supply in plantation forestry, from a private landowner perspective, with an economic opportunity cost. The model is not applicable to low commercial value forest plantations. (C) 2009 Elsevier B.V. All rights reserved.

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Formal elevation facing University of Queensland entrance roads.

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Formal elevation facing University of Queensland entrance roads.

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Formal elevation facing University of Queensland entrance roads.