933 resultados para road tunnel
Resumo:
Iowa's county road system serves many critical functions in a changing environment. Many counties with very different social, economic, and demographic circumstances do not have adequate resources to provide the desired level of service on their secondary road systems. How the state's Road Use Tax Fund (RUTF) is distributed among counties is therefore of great importance. This report presents the results of a year-long study of how to distribute RUTF resources among Iowa's 99 counties. The project was undertaken at the request of county engineers who wish to replace the current method of allocation with one that is more stable, comprehensible, and predictable. This report describes the current allocation method, examines how other states distribute road funds to counties, and discusses potential allocation factors that could be included in a revised procedure. The process undertaken to narrow the range of possible formulas and determine the one to recommend is summarized. Finally, the report presents the allocation formula recommended by the project advisory committee, along with how it would operate.
Resumo:
Iowa's public road system of 112,000 miles is one of the largest and the best in the nation. It represents a considerable financial investment of taxpayer revenues over the years. And, it requires a sustained investment to preserve an economical level of transport service into the future. In 1982, a Governor's Blue Ribbon Transportation Task Force evaluated the effectiveness of Iowa's entire transportation system. Four important Task Force recommendations dealt with public road administrative issues in Iowa. These issues were related to: (1) Design criteria and levels of maintenance; (2) Consistency in the use of standards among jurisdictions; (3) Consolidation of maintenance operations at one jurisdiction level; and (4) Jurisdicational authority for roads; The issues formed the background for Research Project HR-265.
Resumo:
The Iowa counties have been successful in maintaining a good roadway environment on our 90,000 mile secondary road system. However, county highway personnel must remain vigilant in detecting, discovering and correcting potential problems if our roads are to remain so. This presentation was developed for those county personnel who work and travel on secondary roads. The presentation discusses things county personnel can look for during their daily operations which could possibly create a potential problem. If these situations are uncovered and corrected in a timely manner, our secondary road system will be maintained in an appropriate manner.
Resumo:
The objective of this research project was to evaluate the construction and service performance of ammonium phosphate/fly ash (APFA) treated base courses of crushed fines and/or unprocessed sand. Specific test results related to construction of the test sections were included in the 1987 construction report by Iowa State University. The performance of the experimental sections is dealt with in this final report. This 1986 project demonstrated that in all cases the control sections utilizing a Type B base experienced dramatically less cracking in the surface than the APFA treated base sections. The cost per mix and subsequent surface maintenance costs for the APFA base sections, especially those having a substantial amount of limestone, were higher than the Type B base control sections. This type of construction may prove to be economical only when petroleum product costs escalate.
Resumo:
Senate File 2314, 84th General Assembly, states the Iowa Department of Transportation shall submit quarterly reports regarding the implementation of efficiency measures identified in the "Road Use Tax Fund Efficiency Report," January 2012. This report shall provide details of activities undertaken in the previous quarter relating to one-time and long-term program efficiencies and partnership efficiencies. Issues covered include savings realized from the implementation of particular efficiency measures; updates concerning measures that have not been implemented; efforts involving cities, counties, other jurisdiction, or stakeholder interest groups; any new efficiency measures identified or undertaken; and identification of any legislative action that may be required to achieve efficiencies.
Resumo:
Provides instructions for using the computer program which was developed under the research project, "The Economics of Reducing the County Road System: Three Case Studies In Iowa". This program operates on an IBP personal computer with 300K storage. A fixed disk is required with at least 3 megabytes of storage. The computer must be equipped with DOS version 3.0; the programs are written in Fortran. The user's manual describes all data requirements including network preparation, trip information, cost for maintenance, reconstruction, etc. Program operation instructions are presented, as well as sample solution output and a listing of the computer programs.
Resumo:
In this paper is presented a study dealing with the debris flows that reached the national road 7 in January 2005, in the km 1,118.5, Mendoza province. The area is located in the Frontal Cordillera near the limit of the Precordillera. A detailed geomorphologic map has been realized for this study using a Quickbird satellite imagery of the year 2006. Various calculations of volumes, velocities and peak discharges have been performed with the field data and using a geographic information system (GIS). The geomorphologic survey has permitted to propose three propagation scenarios in case of a new event. These allowed creating a map of debris flows susceptibility for the stretch of the road that has been studied. Finally, it has been proposed protection and mitigation measures, based on the results of the study, to protect the road from a new event.
Resumo:
OBJECTIVE: Few epidemiological studies have addressed the health of workers exposed to novel manufactured nanomaterials. The small current workforce will necessitate pooling international cohorts. METHOD: A road map was defined for a globally harmonized framework for the careful choice of materials, exposure characterization, identification of study populations, definition of health endpoints, evaluation of appropriateness of study designs, data collection and analysis, and interpretation of the results. RESULTS: We propose a road map to reach global consensus on these issues. The proposed strategy should ensure that the costs of action are not disproportionate to the potential benefits and that the approach is pragmatic and practical. CONCLUSIONS: We should aim to go beyond the collection of health complaints, illness statistics, or even counts of deaths; the manifestation of such clear endpoints would indicate a failure of preventive measures.
Resumo:
"Metric Training For The Highway Industry", HR-376 was designed to produce training materials for the various divisions of the Iowa DOT, local government and the highway construction industry. The project materials were to be used to introduce the highway industry in Iowa to metric measurements in their daily activities. Five modules were developed and used in training over 1,000 DOT, county, city, consultant and contractor staff in the use of metric measurements. The training modules developed deal with the planning through operation areas of highway transportation. The materials and selection of modules were developed with the aid of an advisory personnel from the highway industry. Each module is design as a four hour block of instruction and a stand along module for specific types of personnel. Each module is subdivided into four chapters with chapter one and four covering general topics common to all subjects. Chapters two and three are aimed at hands on experience for a specific group and subject. This module includes: Module 3 - Road and Bridge Design. This module provides hands on examples of how to use metric measurements in the design of roads and structures.
Resumo:
The peroxisome proliferator-activated receptors (PPARs) are members of the steroid/thyroid nuclear receptor superfamily of ligand-activated transcription factors. To date, three isotypes have been identified, alpha, beta and gamma, encoded by three different genes. The alpha isotype is expressed at high levels in the liver where it has a role in lipid oxidation. Its expression and activity follow a diurnal rhythm that parallels the circulating levels of corticosterone in the bloodstream. The gamma isotype on the other hand, is mainly expressed in adipose tissue and has a critical role in adipocyte differentiation and lipid storage. The function of the ubiquitously expressed isotype, PPAR beta, remains to be determined. Besides fulfilling different roles in lipid metabolism, the different PPAR isotypes also have different ligand specificities. A new approach to identify ligands was developed based on the ligand-dependent interaction of PPAR with the recently characterized co-activator SRC-1. This so-called CARLA assay has allowed the identification of fatty acids and eicosanoids as PPAR ligands. Although the evidence clearly links PPAR isotypes to distinct functions, the molecular basis for this isotype-specificity is still unclear. All three isotypes are able to bind the same consensus response element, formed by a direct repeat of two AGGTCA hexamers separated by one base, though with different affinities. We recently demonstrated that besides the core DR-1 element, the 5' flanking sequence should be included in the definition of a PPRE. Interestingly, the presence of this flanking sequence is of particular importance in the context of PPAR alpha binding. Moreover, it reflects the polarity of the PPAR-RXR heterodimer on DNA, with PPAR binding to the 5' half-site and RXR binding to the 3' half-site. This unusual polarity may confer unique properties to the bound heterodimer with respect to ligand binding and interaction with co-activators and corepressors.
Resumo:
A benefit-cost analysis was used to examine the effects of alternative investment strategies on the local rural road system. The study first estimated the change in costs to the traveling public of various investment strategies, then compared the change for each investment strategy to the cost of implementing that strategy on the county rural road system. The basic purpose of this study was to develop guidelines for local supervisors and engineers in evaluating investment or disinvestment proposals, and to provide information to state legislatures in developing local rural road and bridge policies. Three case study areas of 100 sq mi each were selected in Iowa. A questionnaire was used to collect data from farm and non-farm residents in the study areas. Data were obtained on the number of 1982 trips by origin, destination, and type of vehicle.
Resumo:
Iowa's public road system of 112,000 miles is one of the largest and the best in the nation. It represents a considerable financial investment of taxpayer revenues over the years. And, it requires a sustained investment to preserve an economical level of transport service into the future. In 1982, a Governor's Blue Ribbon Transportation Task Force evaluated the effectiveness of Iowa's entire transportation system. Four important Task Force recommendations dealt with public road administrative issues in Iowa. These issues were related to: 1. design criteria and levels of maintenance 2. consistency in the use of standards among jurisdictions 3. consolidation of maintenance operations at one jurisdictional level and 4. jurisdictional authority for roads. The issues formed the background for Research Project HR-265.
Resumo:
The BPR type Roughometer has been used by the Iowa State Highway Commission since 1955 for the evaluation of the relative roughness of the various Iowa road surfaces. Since the commencement of this program, standardized information about the roughness of the various Iowa roads with respect to their type, construction, location and usage has been obtained. The Roughometer has also served to improve the economics and quality of road construction by making the roughness results of various practices available to all who are interested. In 1965, the Portland Cement Association developed a device known as the PCA Road Meter for measuring road roughness. Mounted in a regular passenger car, the Road Meter is a simple electromechanical device of durable construction which can perform consistently with extremely low maintenance. In 1967, the Iowa State Highway Commission's Laboratory constructed a P.C.A. type Road Meter in order to provide an efficient and reliable method for measuring the Present Serviceability Index for the state's highways. Another possibility was that after considerable testing the Road Meter might eventually replace the Roughometer. Some advantages of the Road Meter over the Roughometer are: (1) Road Meter tests are made by the automobile driver and one assistant without the need of traffic protection. The Roughometer has a crew of four men; two operating the roughometer and two driving safety vehicles. (2) The Road Meter is able to do more miles of testing because of its faster testing speed and the fa.ct that it is the only vehicle involved in the testing. (3) Because of the faster testing speed, the Road Meter gives a better indication of how the road actually rides to the average highway traveler. (4) The cost of operating a Road Meter is less than that of a Roughometer because of the fewer number of vehicles and men needed in testing.
Resumo:
In recent years the Iowa Department of Transportation has shifted emphasis from the construction of new roads to the maintenance and preservation of existing highways. A need has developed for evaluating pavements structurally to select the correct rehabilitation strategy and to properly design a pavement overlay if necessary. Road Rater non-destructive testing has fulfilled this need and has been used successfully to evaluate pavement and subgrade conditions and to design asphaltic concrete overlays and portland cement concrete overlays. The Iowa Road Rater Design Method has been simplified so that it may be easily understood and used by various individuals who are involved in pavement restoration and management. Road Rater evaluation techniques have worked well to date and have been verified by pavement coring, soils sampling and testing. Void detection testing has also been performed, and results indicate that the Road Rater can be used to locate pavement voids and that Road Rater evaluation techniques are reasonably accurate. The success of Road Rater research and development has made dynamic deflection test data an important pavement management input.
Wind Tunnel Analysis of the Effects of Planting at Highway Grade Separation Structures, HR-202, 1979
Resumo:
Blowing and drifting snow has been a problem for the highway maintenance engineer virtually since the inception of the automobile. In the early days, highway engineers were limited in their capability to design and construct drift free roadway cross sections, and the driving public tolerated the delays associated with snow storms. Modern technology, however, has long since provided the design expertise, financial resources, and construction capability for creating relatively snowdrift free highways, and the driver today has come to expect a highway facility that is free of snowdrifts, and if drifts develop they expect highway maintenance crews to open the highway within a short time. Highway administrators have responded to this charge for better control of snowdrifting. Modern highway designs in general provide an aerodynamic cross section that inhibits the deposition of snow on the roadway insofar as it is economically feasible to do so.