26 resultados para Proven Reserves
em Iowa Publications Online (IPO) - State Library, State of Iowa (Iowa), United States
Resumo:
Tillage systems play a significant role in agricultural production throughout Iowa and the Midwest. It has been well documented that increased tillage intensities can reduce soil organic matter in the topsoil due to increased microbial activity and carbon (C ) oxidation. The potential loss of soil organic matter due to tillage operations is much higher for high organic matter soils than low organic matter soils. Tillage effects on soil organic matter can be magnified through soil erosion and loss of soil productivity. Soil organic matter is a natural reservoir for nutrients, buffers against soil erosion, and improves the soil environment to sustain soil productivity. Maintaining soil productivity requires an agriculture management system that maintains or improves soil organic matter content. Combining cropping systems and conservation tillage practices, such as no-tillage, strip-tillage, or ridge-tillage, are proven to be very effective in improving soil organic matter and soil quality.
Resumo:
Four-lane undivided roadways in urban areas can experience a degradation of service and/or safety as traffic volumes increase. In fact, the existence of turning vehicles on this type of roadway has a dramatic effect on both of these factors. The solution identified for these problems is typically the addition of a raised median or two-way left-turn lane (TWLTL). The mobility and safety benefits of these actions have been proven and are discussed in the “Past Research” chapter of this report along with some general cross section selection guidelines. The cost and right-of-way impacts of these actions are widely accepted. These guidelines focus on the evaluation and analysis of an alternative to the typical four-lane undivided cross section improvement approach described above. It has been found that the conversion of a four-lane undivided cross section to three lanes (i.e., one lane in each direction and a TWLTL) can improve safety and maintain an acceptable level of service. These guidelines summarize the results of past research in this area (which is almost nonexistent) and qualitative/quantitative before-and-after safety and operational impacts of case study conversions located throughout the United States and Iowa. Past research confirms that this type of conversion is acceptable or feasible in some situations but for the most part fails to specifically identify those situations. In general, the reviewed case study conversions resulted in a reduction of average or 85th percentile speeds (typically less than five miles per hour) and a relatively dramatic reduction in excessive speeding (a 60 to 70 percent reduction in the number of vehicles traveling five miles per hour faster than the posted speed limit was measured in two cases) and total crashes (reductions between 17 to 62 percent were measured). The 13 roadway conversions considered had average daily traffic volumes of 8,400 to 14,000 vehicles per day (vpd) in Iowa and 9,200 to 24,000 vehicles per day elsewhere. In addition to past research and case study results, a simulation sensitivity analysis was completed to investigate and/or confirm the operational impacts of a four-lane undivided to three-lane conversion. First, the advantages and disadvantages of different corridor simulation packages were identified for this type of analysis. Then, the CORridor SIMulation (CORSIM) software was used x to investigate and evaluate several characteristics related to the operational feasibility of a four-lane undivided to three-lane conversion. Simulated speed and level of service results for both cross sections were documented for different total peak-hour traffic, access densities, and access-point left-turn volumes (for a case study corridor defined by the researchers). These analyses assisted with the identification of the considerations for the operational feasibility determination of a four -lane to three-lane conversion. The results of the simulation analyses primarily confirmed the case study impacts. The CORSIM results indicated only a slight decrease in average arterial speed for through vehicles can be expected for a large range of peak-hour volumes, access densities, and access-point left-turn volumes (given the assumptions and design of the corridor case study evaluated). Typically, the reduction in the simulated average arterial speed (which includes both segment and signal delay) was between zero and four miles per hour when a roadway was converted from a four-lane undivided to a three-lane cross section. The simulated arterial level of service for a converted roadway, however, showed a decrease when the bi-directional peak-hour volume was about 1,750 vehicles per hour (or 17,500 vehicles per day if 10 percent of the daily volume is assumed to occur in the peak hour). Past research by others, however, indicates that 12,000 vehicles per day may be the operational capacity (i.e., level of service E) of a three-lane roadway due to vehicle platooning. The simulation results, along with past research and case study results, appear to support following volume-related feasibility suggestions for four-lane undivided to three-lane cross section conversions. It is recommended that a four-lane undivided to three-lane conversion be considered as a feasible (with respect to volume only) option when bi-directional peak-hour volumes are less than 1,500 vehicles per hour, but that some caution begin to be exercised when the roadway has a bi-directional peak-hour volume between 1,500 and 1,750 vehicles per hour. At and above 1,750 vehicles per hour, the simulation indicated a reduction in arterial level of service. Therefore, at least in Iowa, the feasibility of a four-lane undivided to three-lane conversion should be questioned and/or considered much more closely when a roadway has (or is expected to have) a peak-hour volume of more than 1,750 vehicles. Assuming that 10 percent of the daily traffic occurs during the peak-hour, these volume recommendations would correspond to 15,000 and 17,500 vehicles per day, respectively. These suggestions, however, are based on the results from one idealized case xi study corridor analysis. Individual operational analysis and/or simulations should be completed in detail once a four-lane undivided to three-lane cross section conversion is considered feasible (based on the general suggestions above) for a particular corridor. All of the simulations completed as part of this project also incorporated the optimization of signal timing to minimize vehicle delay along the corridor. A number of determination feasibility factors were identified from a review of the past research, before-and-after case study results, and the simulation sensitivity analysis. The existing and expected (i.e., design period) statuses of these factors are described and should be considered. The characteristics of these factors should be compared to each other, the impacts of other potentially feasible cross section improvements, and the goals/objectives of the community. The factors discussed in these guidelines include • roadway function and environment • overall traffic volume and level of service • turning volumes and patterns • frequent-stop and slow-moving vehicles • weaving, speed, and queues • crash type and patterns • pedestrian and bike activity • right-of-way availability, cost, and acquisition impacts • general characteristics, including - parallel roadways - offset minor street intersections - parallel parking - corner radii - at-grade railroad crossings xii The characteristics of these factors are documented in these guidelines, and their relationship to four-lane undivided to three-lane cross section conversion feasibility identified. This information is summarized along with some evaluative questions in this executive summary and Appendix C. In summary, the results of past research, numerous case studies, and the simulation analyses done as part of this project support the conclusion that in certain circumstances a four-lane undivided to three-lane conversion can be a feasible alternative for the mitigation of operational and/or safety concerns. This feasibility, however, must be determined by an evaluation of the factors identified in these guidelines (along with any others that may be relevant for a individual corridor). The expected benefits, costs, and overall impacts of a four-lane undivided to three-lane conversion should then be compared to the impacts of other feasible alternatives (e.g., adding a raised median) at a particular location.
Resumo:
This is your employee handbook. This information is based on Iowa Department of Administrative Services – Human Resources Enterprise (DAS-HRE) rules and policies. Much of the information in this handbook is also covered in the State’s collective bargaining agreements. Where there are differences between a collective bargaining agreement and this handbook, the collective bargaining agreement prevails for employees covered by the agreement. Where there are differences between this handbook and DAS-HRE rules and policies, DAS-HRE rules and policies prevail. Some of the employee benefit plans described in this handbook are subject to legal requirements concerning reporting and disclosure. This handbook contains highlights of those plans. For complete details about benefit plans, consult the benefit handbooks and the official plan documents. In case of any discrepancy, the official plan documents prevail. Of course, changes in laws may affect the benefit programs described in this handbook. The State of Iowa reserves the right to amend the contents of this handbook at any time without prior notice. The provisions of this handbook and other policies do not establish contractual rights or conditions of employment between the State and its employees.
Resumo:
Helping families, businesses and communities rebuild after the floods and tornadoes of 2008 remains a top priority. That is why Governor Chet Culver has asked for the first bill sent to him by the Iowa General Assembly in 2009 to be the Rebuild Iowa bill: a $43 million measure, funded from Iowa’s historic cash reserves.
Resumo:
I hope you will find a great deal of challenge and personal satisfaction in your employment with the State. You have an important role in accomplishing the goals of your department and of state government. The State has a proud tradition built on the excellence of its employees and their work. We challenge you to help maintain and improve upon this tradition. You soon will discover that our pride is contagious! As a state employee, it is very important that you always present the best possible image to the public. Remember to act promptly, be courteous, and treat people, our customers, respectfully. Your actions will make a lasting impression .... be sure it is a positive one. This is your employee handbook. This information is based on Iowa Department of Administrative Services – Human Resources Enterprise (DAS-HRE) rules and policies. Much of the information in this handbook is also covered in the State’s collective bargaining agreements. Where there are differences between a collective bargaining agreement and this handbook, the collective bargaining agreement prevails for employees covered by the agreement. Where there are differences between this handbook and DAS-HRE rules and policies, DAS-HRE rules and policies prevail. Some of the employee benefit plans described in this handbook are subject to legal requirements concerning reporting and disclosure. This handbook contains highlights of those plans. For complete details about benefit plans, consult the benefit handbooks and the official plan documents. In case of any discrepancy, the official plan documents prevail. Of course, changes in laws may affect the benefit programs described in this handbook. The State of Iowa reserves the right to amend the contents of this handbook at any time without prior notice. The provisions of this handbook and other policies do not establish contractual rights or conditions of employment between the State and its employees.
Resumo:
The Main Street Four Point Approach® is a proven development process and has provided both focus and opportunity to Iowa’s participating cities. Collectively, these progressive communities have documented thousands of volunteer hours and millions of dollars in private investment into the revitalization of their historic city centers.
Resumo:
Drug use is a preventable behavior; drug addiction is a treatable disease; and a balanced approach of proven and promising prevention, treatment and enforcement is required to protect Iowans from drugs now and in the future. Drug abuse itself is a two-faceted problem, affected by both the available supply of and the demand for illegal drugs and other substances of abuse. Any strategy dealing with both the supply of and demand for drugs of abuse must be three-fold and involve these coordinated components: 1) Prevention strategies to discourage the initial human demand for drugs, 2) Treatment for those who already abuse or are addicted to drugs, in order to halt their drug-seeking behavior, and 3) Law enforcement actions to decrease the supply of illegal drugs and bring to treatment those who otherwise would not seek help. It is with these three approaches in mind that the Governor’s Office of Drug Control Policy presents the 2012 Iowa Drug Control Strategy. Mark J. Schouten Director, Governor’s Office of Drug Control Policy
Resumo:
The purpose of this guide is to help practitioners understand how to optimize concrete pavement joint performance through the identification, mitigation, and prevention of joint deterioration. It summarizes current knowledge from research and practice to help practitioners access the latest knowledge and implement proven techniques. Emphasizing that water is the common factor in most premature joint deterioration, this guide describes various types of joint deterioration that can occur. Some distresses are caused by improper joint detailing or construction, and others can be attributed to inadequate materials or proportioning. D cracking is a form of joint distress that results from the use of poor-quality aggregates. A particular focus in this guide is joint distress due to freeze-thaw action. Numerous factors are at play in the occurrence of this distress, including the increased use of a variety of deicing chemicals and application strategies. Finally, this guide provides recommendations for minimizing the potential for joint deterioration, along with recommendations for mitigation practices to slow or stop the progress of joint deterioration.
Resumo:
This report documents Phase IV of the Highway Maintenance Concept Vehicle (HMCV) project, a pooled fund study sponsored by the Departments of Transportation of Iowa, Pennsylvania, and Wisconsin. This report provides the background, including a brief history of the earlier phases of the project, a systems overview, and descriptions of the research conducted in Phase IV. Finally, the report provides conclusions and recommendations for future research. Background The goal of the Highway Maintenance Concept Vehicle Pooled Fund Study is to provide travelers with the level of service defined by policy during the winter season at the least cost to taxpayers. This goal is to be accomplished by using information regarding actual road conditions to facilitate and adjust snow and ice control activities. The approach used in this study was to bring technology applications from other industries to the highway maintenance vehicle. This approach is evolutionary in that as emerging technologies and applications are found to be acceptable to the pooled fund states and as they appear that to have potential for supporting the study goals they become candidates for our research. The objective of Phase IV is to: Conduct limited deployment of selected technologies from Phase III by equipping a vehicle with proven advanced technologies and creating a mobile test laboratory for collecting road weather data. The research quickly pointed out that investments in winter storm maintenance assets must be based on benefit/cost analysis and related to improving level of service. For example, Iowa has estimated the average cost of fighting a winter storm to be about $60,000 to $70,000 per hour typically. The maintenance concept vehicle will have advanced technology equipment capable of applying precisely the correct amount of material, accurately tailored to the existing and predicted pavement conditions. Hence, a state using advanced technology could expect to have a noticeable impact on the average time taken to establish the winter driving service level. If the concept vehicle and data produced by the vehicle are used to support decision-making leading to reducing material usage and the average time by one hour, a reasonable benefit/cost will result. Data from the friction meter can be used to monitor and adjust snow and ice control activities and inform travelers of pavement surface conditions. Therefore, final selection of successfully performing technologies will be based on the foundation statements and criteria developed by the study team.
Resumo:
Single-vehicle run-off-road crashes are the most common crash type on rural two-lane Iowa roads. Rumble strips have proven effective in mitigating these crashes, but the strips are commonly installed in paved shoulders on higher-volume roads that are owned by the State of Iowa. Lower-volume paved rural roads owned by local agencies do not commonly feature paved shoulders but frequently experience run-off-road crashes. This project involved installing rumble stripes, which are a combination of conventional rumble strips with a painted edge line placed on the surface of the milled area, along the edge of the travel lanes, but at a narrow width to avoid possible intrusion into the normal vehicle travel paths. The research described in this report was part of a project funded by the Federal Highway Administration, Iowa Highway Research Board, and Iowa Department of Transportation to evaluate the effectiveness of edge-line rumble strips in Iowa. The project evaluated the effectiveness of rumble stripes in reducing run-off-road crashes and in improving the longevity and wet-weather visibility of edge-line markings. This project consisted of two phases. The first phase was to select pilot study locations, select a set of test sites, install rumble stripes, summarize lessons learned during installation, and provide a preliminary assessment of the rumble stripes’ performance. The purpose of this report was to document results from Phase II. A before and after crash analysis was conducted to assess whether use of the treatment had resulted in fewer crashes. However, due to low sample size, results of the analysis were inconclusive. Lateral position was also evaluated before and after installation of the treatment to determine whether vehicles engaged in better lane keeping. Pavement marking wear was also assessed.
Resumo:
Many would argue that the dramatic rise in autism has reached critical mass, and this council echoes that statement. Iowa, like many states in the nation, is currently ill equipped to handle the large influx of children and adults with autism. When this council was initially formed we were facing diagnosis rates of 1 in 150 and currently the diagnosis rate is 1 in 91. Current resource strains in education, qualified trained professionals, access to care, and financial services are rapidly deteriorating Iowa’s ability to deliver quality services to children, adults, and families affected by autism. If Iowa leadership fails to act quickly the already strained system will face a breaking point in the following areas: financing, coordination of care, educational resources, early identification, adult services, and access to service delivery - just to name a few. This council has taken the past 12 plus months hearing testimony from state officials, providers, and caregivers to ensure that care for those with autism is effective, cost efficient, and accessible. This council will be making recommendations on three major areas; early identification, seamless support/coordination of care, and financing of care. While these areas will be highlighted in this first annual report it in no way minimizes other areas that need to be addressed such as early intervention, special education, training, in-home support services, financing options, and data collection. Implementing the initial recommendations of this council will lay foundational support for the areas mentioned above. Often those in position to help ask what can be done to help families in Iowa. This council has provided a roadmap to help facilitate effective and proven treatments to children and adults with autism.
Resumo:
County engineers in Iowa face the dual problems of rapidly escalating costs and a decreasing rate of growth of revenues. Various priority systems are in use, ranking projects for inclusion in road improvement programs, but they generally have weaknesses when used to compare one project with another in a different location. The sufficiency rating system has proven to be a useful tool in developing a priority list of projects for primary road systems, but there are none currently in use for secondary road systems. The research reported here was undertaken to develop a sufficiency rating system which could be used for secondary roads in Iowa and to produce the necessary forms and instructions to aid county engineering personnel in their efforts to complete the ratings for roads within their county.
Resumo:
Iowa's secondary roads contain nearly 15,000 bridges which are less than 40 ft (12.2 m) in length. Many of these bridges were built several decades ago and need to be replaced. Box culvert construction has proven to be an adequate bridge replacement technique. Recently a new bridge replacement alternative, called the Air-O-Form method, has emerged which has several potential advantages over box culvert construction. This new technique uses inflated balloons as the interior form in the construction of an arch culvert. Concrete was then shotcreted onto the balloon form. The objective of research project HR-313 was to construct an air formed arch culvert to determine the applicability of the Air-O-Form technique as a county bridge replacement alternative. The project had the following results: The Air-O-Form method can be used to construct a structurally sound arch culvert; and the method must become more economical if it is to compete with box culverts. Continued monitoring should be conducted in order to evaluate the long-term performance of the Air-O-Form method.
Resumo:
Iowa's secondary road network contains nearly 15,000 bridges which are less than 12 m (40 ft) long. Many of these bridges were built several decades ago and need to be replaced. Box culvert construction has proven to be an adequate bridge replacement technique. An alternative to box culverts is the Air-O-Form method of arch culvert construction. The Air-O-Form method has several potential advantages over box culvert construction. The new technique uses inflated balloons as the interior form in the construction of an arch culvert. Concrete is then shotcreted onto the balloon form to complete the arch culvert. The objective of the research project was to construct an air formed arch culvert to determine its applicability as an alternative county bridge replacement technique. The project had the following results: (1) The Air-O-Form method can be used to construct a structurally sound arch culvert; and (2) The method must become more economical if it is to compete with box culverts.
Resumo:
The Road Rater is a dynamic deflection measuring appa-ratus for flexible base pavements. The basic operating principle of the Road Rater is to impart a dynamic loading and measure the resultant movement of the pavement with velocity sensors. This data, when properly adjusted for temperature by use of a nomograph included in this report, can be used to determine pavement life expectancy and estimate overlay thickness required. Road Rater testing will be conducted in the spring, when pave-ments are in their weakest condition, until seasonal correction factors can be developed. The Road Rater does not have sufficient ram weight to effectively evaluate load carrying capacity of rigid pavements. All rigid pavements react similarly to Road Rater testing and generally deflect from 0.65 to 1.30 mils. Research will be continued to evaluate rigid pavements with the Road Rater, however. The Road Rater has proven to be a reliable, trouble free pavement evaluation machine. The deflection apparatus was originally front-mounted, but was rear-mounted during the winter of 1977-78. Since that time, van handling has greatly improved, and front suspension parts are no longer overstressed due to improper weight distribution. The Road Rater provides a fast, economical, nondestructive test method to evaluate flexible pavements. Road Rater test data can be used to predict pavement life, set priorities for asphaltic concrete resurfacing, and design asphaltic concrete overlays. Temperature and seasonal variations significantly affect Road Rater deflection readings and must be considered. A nomograph included in this report adjusts for temperature, but does not correct for seasonal effect. Road Rater testing will be conducted in the spring until seasonal correction factors can be developed. The Road Rater has not successfully evaluated rigid pavements, but research will continue in this area. 1. Recommendations for continuing Road Rater research, evaluation and application are as follows:A computer program should be established to reduce Road Rater raw data (Range and Sensor reading) to HR-178 Road Rater Dynamic Deflections For Determining Structural Rating Of Flexible Pavements mean deflection (mils) and/or structural rating. This computer printout would be similar to present friction testing printouts, and would greatly reduce Road Rater data reduction manpower needs and costs. 2. Seasonal variation study should continue to develop seasonal correction factors. Seasonal test roads will be studied concurrently with routine testing during 1979 to develop this relationship. All Road Rater testing will be conducted in the spring until the seasonal relationship is established. 3. An asphaltic concrete overlay design method should be established based on Road Rater de-flection readings. The AASHTO Interim Guide for Design of Pavement Structures 1972 will be used as a base document for this study. 4. AASHTO Structural numbers should be compared to Road Rater Structural Ratings during 1979 on asphaltic concrete overlay projects. This analysis will enable us to refine Road Rater evaluation of flexible pavements. Roads will be tested before resurfacing and several months