Synthesis of Best Practice for Increasing Protection and Visibility of Highway Maintenance Vehicles, CTRE Final Report Iowa DOT Project TR-475, August 2002

The purpose of this research project is to study current practices in enhancing visibility and protection of highway maintenance vehicles involved in moving operations such as snow removal and shoulder operations, crack sealing, and pothole patching. The results will enable the maintenance staff to adequately assess the applicability and impact of each strategy to their use and budget. The report’s literature review chapter examines the use of maintenance vehicle warning lights, retroreflective tapes, shadow vehicles and truck-mounted attenuators, and advanced vehicle control systems, as well as other practices to improve visibility for both snowplow operators and vehicles. The chapter concludes that the Manual on Uniform Traffic Control Devices does not specify what color or kind of warning lights to use. Thus, a wide variety of lights are being used on maintenance vehicles. The study of the relevant literatures also suggests that there are no clear guidelines for moving work zones at this time. Two types of surveys were conducted to determine current practices to improve visibility and safety in moving work zones across the country and in the state of Iowa. In the first survey of state departments of transportation, most indicated using amber warning lights on their maintenance vehicles. Almost all the responding states indicated using some form of reflective material on their vehicles to make them more visible. Most participating states indicated that the color of their vehicles is orange. Most states indicated using more warning lights on snow removal vehicles than their other maintenance vehicles. All responding state agencies indicated using shadow vehicles and/or truck-mounted attenuators during their moving operations. In the second survey of Iowa counties, most indicated using very similar traffic control and warning devices during their granular road maintenance and snow removal operations. Mounting warning signs and rotating or strobe lights on the rear of maintenance vehicles is common for Iowa counties. The most common warning devices used during the counties’ snow removal operations are reflective tapes, warning flags, strobe lights, and auxiliary headlamps.

The Rapid Rise of China’s Dairy Sector: Factors Behind the Growth in Demand and Supply, May 2005

With the rapid growth in China’s dairy industry, a number of recent papers have addressed either the supply or the demand trends for dairy products in China. None, however, presents a systematic explanation for the recent growth in both the supply and demand for dairy products. The goal of this paper is to sketch a more comprehensive picture of China’s dairy sector and to assess the nature of the sector’s development in the coming decades. Drawing upon several empirical studies, we examine the trends in dairy product consumption to create a composite picture of the factors underlying the recent growth. We also empirically investigate the sources of production gains in milk supply and assess the relative importance of expanding herd size, changes in the nature of production, technological change, and improvements in efficiency to the overall growth of milk production.

Synthesis of Nondestructive Testing Technologies for Geomaterial Applications, May 2005

Current monitoring techniques for determination of compaction of earthwork and asphalt generally involve destructive testing of the materials following placement. Advances in sensor technologies show significant promise for obtaining necessary information through nondestructive and remote techniques. To develop a better understanding of suitable and potential technologies, this study was undertaken to conduct a synthesis review of nondestructive testing technologies and perform preliminary evaluations of selected technologies to better understand their application to testing of geomaterials (soil fill, aggregate base, asphalt, etc.). This research resulted in a synthesis of potential technologies for compaction monitoring with a strong emphasis on moisture sensing. Techniques were reviewed and selectively evaluated for their potential to improve field quality control operations. Activities included an extensive review of commercially available moisture sensors, literature review, and evaluation of selected technologies. The technologies investigated in this study were dielectric, nuclear, near infrared spectroscopy, seismic, electromagnetic induction, and thermal. The primary disadvantage of all the methods is the small sample volume measured. In addition, all the methods possessed some sensitivity to non-moisture factors that affected the accuracy of the results. As the measurement volume increases, local variances are averaged out providing better accuracy. Most dielectric methods with the exception of ground penetrating radar have a very small measurement volume and are highly sensitive to variations in density, porosity, etc.

Developing a Simple and Rapid Test for Monitoring the Heat Evolution of Concrete Mixtures for Both Laboratory and Field Applications, January 2006

Various test methods exist for measuring heat of cement hydration; however, most current methods require expensive equipment, complex testing procedures, and/or extensive time, thus not being suitable for field application. The objectives of this research are to identify, develop, and evaluate a standard test procedure for characterization and quality control of pavement concrete mixtures using a calorimetry technique. This research project has three phases. Phase I was designed to identify the user needs, including performance requirements and precision and bias limits, and to synthesize existing test methods for monitoring the heat of hydration, including device types, configurations, test procedures, measurements, advantages, disadvantages, applications, and accuracy. Phase II was designed to conduct experimental work to evaluate the calorimetry equipment recommended from the Phase I study and to develop a standard test procedure for using the equipment and interpreting the test results. Phase II also includes the development of models and computer programs for prediction of concrete pavement performance based on the characteristics of heat evolution curves. Phase III was designed to study for further development of a much simpler, inexpensive calorimeter for field concrete. In this report, the results from the Phase I study are presented, the plan for the Phase II study is described, and the recommendations for Phase III study are outlined. Phase I has been completed through three major activities: (1) collecting input and advice from the members of the project Technical Working Group (TWG), (2) conducting a literature survey, and (3) performing trials at the CP Tech Center’s research lab. The research results indicate that in addition to predicting maturity/strength, concrete heat evolution test results can also be used for (1) forecasting concrete setting time, (2) specifying curing period, (3) estimating risk of thermal cracking, (4) assessing pavement sawing/finishing time, (5) characterizing cement features, (6) identifying incompatibility of cementitious materials, (7) verifying concrete mix proportions, and (8) selecting materials and/or mix designs for given environmental conditions. Besides concrete materials and mix proportions, the configuration of the calorimeter device, sample size, mixing procedure, and testing environment (temperature) also have significant influences on features of concrete heat evolution process. The research team has found that although various calorimeter tests have been conducted for assorted purposes and the potential uses of calorimeter tests are clear, there is no consensus on how to utilize the heat evolution curves to characterize concrete materials and how to effectively relate the characteristics of heat evolution curves to concrete pavement performance. The goal of the Phase II study is to close these gaps.

Consumer Advisory Bulletin, Rapid Tax-Refund Loans A very costly way to gain just a few days on tax refunds, January 2008

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Rapid Tax-Refund Loans A very costly way to gain just a few days on tax refunds.

Consumer Advisory Bulletin, Avoid Rapid Tax-Refund Loans December, 2008

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoid Rapid Tax-Refund Loans

Consumer Advisory Bulletin, Avoid Rapid Tax-Refund Loans December, 2008

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoid Rapid Tax-Refund Loans

Consumer Advisory Bulletin, Avoid Rapid Tax-Refund Loans February, 2009

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoid Rapid Tax-Refund Loans

Consumer Advisory Bulletin; Beware of Avoid Rapid Tax-Refund Loans, February 2010

The Attorney General’s Consumer Protection Division receives hundreds of calls and consumer complaints every year. Follow these tips to avoid unexpected expense and disappointments. This record is about: Avoid Rapid Tax-Refund Loans

Clear Zone – A Synthesis of Practice and an Evaluation of the Benefi ts of Meeting the 10-ft Clear Zone Goal on Urban Streets, November 2008

In urban communities, there are often limited amounts of right-of-way available for establishing a large setback distance from the curb for fixed objects. Urban communities must constantly weigh the cost of purchasing additional right-of-way for clear zones against the risk of fixed object crashes. From 2004 to 2006, this type of crash on curbed roads represented 15% of all fatal crashes and 3% of all crashes in the state of Iowa. Many states have kept the current minimum AASHTO recommendations as their minimum clear zone standards; however, other states have decided that these recommendations are insufficient and have increased the required minimum clear zone distance to better suit the judgment of local designers. This report presents research on the effects of the clear zone on urban curbed streets. The research was conducted in two phases. The first phase involved a synthesis of practice that included a literature review and a survey of practices in jurisdictions that have developmental and historical patterns similar to those of Iowa. The second phase involved investigating the benefits of a 10 ft clear zone, which included examining urban corridors in Iowa that meet or do not meet the 10 ft clear zone goal. The results of this study indicate that a consistent fixed object offset results in a reduction in the number of fixed object crashes, a 5 ft clear zone is most effective when the goal is to minimize the number of fixed object c ashes, and a 3 ft clear zone is most effective when the goal is to minimize the cost of fixed object crashes.

Durable, Cost-Effective Pavement Markings Phase I: Synthesis of Current Research, June 2001

Pavement marking technology is a continually evolving subject. There are numerous types of materials used in the field today, including (but not limited to) paint, epoxy, tape, and thermoplastic. Each material has its own set of unique characteristics related to durability, retro reflectivity, installation cost, and life-cycle cost. The Iowa Highway Research Board was interested in investigating the possibility of developing an ongoing program to evaluate the various products used in pavement marking. This potential program would maintain a database of performance and cost information to assist state and local agencies in determining which materials and placement methods are most appropriate for their use. The Center for Transportation Research and Education at Iowa State University has completed Phase I of this research: to identify the current practice and experiences from around the United States to recommend a further course of action for the State of Iowa. There has been a significant amount of research completed in the last several years. Research from Michigan, Pennsylvania, South Dakota, Ohio, and Alaska all had some common findings: white markings are more retro reflective than yellow markings; paint is by-and-large the least expensive material; paint tends to degrade faster than other materials; thermoplastic and tapes had higher retro reflective characteristics. Perhaps the most significant program going on in the area of pavement markings is the National Transportation Product Evaluation Program (NTPEP). This is an ongoing research program jointly conducted by the American Association of State Highway and Transportation Officials and its member states. Field and lab tests on numerous types of pavement marking materials are being conducted at sites representing four climatological areas. These results are published periodically for use by any jurisdiction interested in pavement marking materials performance.At this time, it is recommended that the State of Iowa not embark on a test deck evaluation program. Instead, close attention should be paid to the ongoing evaluations of the NTPEP program. Materials that fare well on the NTPEP test de cks should be considered for further field studies in Iowa.

Durable, Cost-Effective Pavement Markings Phase I: Synthesis of Current Reseaech, June 2001

Pavement marking technology is a continually evolving subject. There are numerous types of materials used in the field today, including (but not limited to) paint, epoxy, tape, and thermoplastic. Each material has its own set of unique characteristics related to durability, retroreflectivity, installation cost, and life-cycle cost. The Iowa Highway Research Board was interested in investigating the possibility of developing an ongoing program to evaluate the various products used in pavement marking. This potential program would maintain a database of performance and cost information to assist state and local agencies in determining which materials and placement methods are most appropriate for their use. The Center for Transportation Research and Education at Iowa State University has completed Phase I of this research: to identify the current practice and experiences from around the United States to recommend a further course of action for the State of Iowa. There has been a significant amount of research completed in the last several years. Research from Michigan, Pennsylvania, South Dakota, Ohio, and Alaska all had some common findings: white markings are more retroreflective than yellow markings; paint is by-and-large the least expensive material; paint tends to degrade faster than other materials; thermoplastic and tapes had higher retroreflective characteristics. Perhaps the most significant program going on in the area of pavement markings is the National Transportation Product Evaluation Program (NTPEP). This is an ongoing research program jointly conducted by the American Association of State Highway and Transportation Officials and its member states. Field and lab tests on numerous types of pavement marking materials are being conducted at sites representing four climatological areas. These results are published periodically for use by any jurisdiction interested in pavement marking materials performance. At this time, it is recommended that the State of Iowa not embark on a test deck evaluation program. Instead, close attention should be paid to the ongoing evaluations of the NTPEP program. Materials that fare well on the NTPEP test de cks should be considered for further field studies in Iowa.

Erosion Control for Highway Applications, Phase I: Review and Synthesis of Literature, Final Report, TR-464, May 2002

The project described herein has led to a convenient, computer-based expert system for identifying and evaluating potentially effective erosion- and sedimentation-control measures for use in roadway construction throughout Iowa and elsewhere in the Midwest. The expert system is intended to be an accessible and efficient practical resource to aid state, county, and municipal engineers in the selection of the best management practices for preventing unwanted erosion and sedimentation at roadway construction sites, during and after construction.

Non-Destructive Evaluation of Iowa Pavements Phase 2: Development of a Fully Automated Software System for Rapid Analysis/Processing of the Falling Weight Deflectometer Data, 2009

The Office of Special Investigations at Iowa Department of Transportation (DOT) collects FWD data on regular basis to evaluate pavement structural conditions. The primary objective of this study was to develop a fully-automated software system for rapid processing of the FWD data along with a user manual. The software system automatically reads the FWD raw data collected by the JILS-20 type FWD machine that Iowa DOT owns, processes and analyzes the collected data with the rapid prediction algorithms developed during the phase I study. This system smoothly integrates the FWD data analysis algorithms and the computer program being used to collect the pavement deflection data. This system can be used to assess pavement condition, estimate remaining pavement life, and eventually help assess pavement rehabilitation strategies by the Iowa DOT pavement management team. This report describes the developed software in detail and can also be used as a user-manual for conducting simulation studies and detailed analyses. *********************** Large File ***********************

Synthesis of Work-Zone Performance Measures, TPF-5(081), 2013

The main objective of this synthesis was to identify and summarize how agencies collect, analyze, and report different work-zone traffic-performance measures, which include exposure, mobility, and safety measures. The researchers also examined communicating performance to the public. This toolbox provides knowledge to help state departments of transportation (DOTs), as well as counties and cities, to better address reporting of work-zone performance.