CP Road MAP Brief 13-1, August 2010

Describing promising technologies that can be used now to enhance concrete paving practices

An Investigation of the Interstate 80 Rutting in Adair County, October 1983

This investigation was initiated to determine the causes of a rutting problem that occurred on Interstate 80 in Adair County. 1-80 from Iowa 25 to the Dallas County line was opened to traffic in November, 1960. The original pavement consisted of 4-1/2" of asphalt cement concrete over 12" of rolled stone base and 12" of granular subbase. A 5-1/2" overlay of asphalt cement concrete was placed in 1964. In 1970-1972, the roadway was resurfaced with 3" of asphalt cement concrete. In 1982, an asphalt cement concrete inlay, designed for a 10-year life, was placed in the eastbound lane. The mix designs for all courses met or exceeded all current criteria being used to formulate job mixes. Field construction reports indicate .that asphalt usage, densities, field voids and filler bitumen determinations were well within specification limits on a very consistent basis. Field laboratory reports indicate that laboratory voids for the base courses were within the prescribed limits for the base course and below the prescribed limits for the surface course. Instructional memorandums do indicate that extreme caution should be exercised when the voids are at or near the lower limits and traffic is not minimal. There is also a provision that provides for field voids controlling when there is a conflict between laboratory voids and field voids. It appears that contract documents do not adequately address the directions that must be taken when this conflict arises since it can readily be shown that laboratory voids must be in the very low or dangerous range if field voids are to be kept below the maximum limit under the current density specifications. A rut depth survey of January, 1983, identified little or no rutting on this section of roadway. Cross sections obtained in October, 1983, identified rutting which ranged from 0 to 0.9" with a general trend of the rutting to increase from a value of approximately 0.3" at MP 88 to a rut depth of 0.7" at MP 98. No areas of significant rutting were identified in the inside lane. Structural evaluation with the Road Rater indicated adequate structural capacity and also indicated that the longitudinal subdrains were functioning properly to provide adequate soil support values. Two pavement sections taken from the driving lane indicated very little distortion in the lower 7" base course. Essentially all of the distortion had occurred in the upper 2" base course and the 1..;1/2" surface course. Analysis of cores taken from this section of Interstate 80 indicated very little densification of either the surface or the upper or lower base courses. The asphalt cement content of both the Type B base courses and the Type A surface course were substantially higher than the intended asphalt cement content. The only explanation for this is that the salvaged material contained a greater percent of asphalt cement than initial extractions indicated. The penetration and viscosity of the blend of new asphalt cement and the asphalt cement recovered from the salvaged material were relatively close to that intended for this project. The 1983 ambient temperatures were extremely high from June 20 through September 10. The rutting is a result of a combination of adverse factors including, (1) high asphalt content, (2) the difference between laboratory and field voids, (3) lack of intermediate sized crushed particles, (4) high ambient temperatures. The high asphalt content in the 2" upper base course produced an asphalt concrete mix that did not exhibit satisfactory resistance to deformation from heavy loading. The majority of the rutting resulted from distortion of the 2" upper base lift. Heater planing is recommended as an interim corrective action. Further recommendation is to design for a 20-year alternative by removing 2-1/2" of material from the driving lane by milling and replacing with 2-1/2" of asphalt concrete with improved stability. This would be .followed by placing 1-1/2" of high quality resurfacing on the entire roadway. Other recommendations include improved density and stability requirements for asphalt concrete on high traffic roadways.

Interstate 74 Quad Cities Corridor Study Scott County, Iowa and Rock Island County, Illinois Project Number IM-74-1(122)0-13-82 FHWA-IOWA-EIS-09-01-F, February 2009

The Federal Highway Administration (FHWA) and the Iowa and Illinois Departments of Transportation (Iowa DOT and IDOT) have identified the Selected Alternative for improving Interstate 74 (I-74) from its southern terminus at Avenue of the Cities (23rd Avenue) in Moline, Illinois to its northern terminus one mile north of the I-74 interchange with 53rd Street in Davenport, Iowa. The Selected Alternative identified and discussed in this Record of Decision is the preferred alternative identified in the Final Environmental Impact Statement (FEIS). The purpose of the proposed improvements is to improve capacity, travel reliability, and safety along I-74 between its termini, and provide consistency with local land use planning goals. The need for the proposed improvements to the I-74 corridor is based on a combination of factors related to providing better transportation service and sustaining economic development.

Evaluation of Rumble Stripes on Low-Volume Rural Roads in Iowa—Phase II Final Report, November 2011

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.

Utilization of Remote Traffic Monitoring Devices for Urban Freeway Work Zone Assessment Final Report, January 2012

The objective of this project was to promote and facilitate analysis and evaluation of the impacts of road construction activities in Smart Work Zone Deployment Initiative (SWZDI) states. The two primary objectives of this project were to assess urban freeway work-zone impacts through use of remote monitoring devices, such as radar-based traffic sensors, traffic cameras, and traffic signal loop detectors, and evaluate the effectiveness of using these devices for such a purpose. Two high-volume suburban freeway work zones, located on Interstate 35/80 (I-35/I-80) through the Des Moines, Iowa metropolitan area, were evaluated at the request of the Iowa Department of Transportation (DOT).

Performance of Strip Seals in Iowa Bridges, Project TR-437, January 2001

A pilot study was conducted on the premature failures of neoprene strip seals in expansion joints in Iowa bridges. In a relatively large number of bridges, strip seals have pulled out of the steel extrusions or otherwise failed well before the expected life span of the seal. The most serious consequence of a strip-seal failure is damage to the bridge substructure due to salt, water, and debris interacting with the substructure. A literature review was performed. Manufacturers’ specifications and recommendations, practices in the states bordering Iowa, and Iowa DOT design and installation guidelines were reviewed. Discussions were held with bridge contractors and the installation of a strip seal system was observed. Iowa DOT bridge databases were analyzed. A national survey was conducted on the use and performance of strip seals. With guidance from the Iowa DOT, twelve in-service bridges with strip-seal expansion joints were selected for detailed investigation. Effective bridge temperatures and corresponding expansion-joint openings were measured, DOT inspection reports were reviewed, and likely cause(s) of premature failures of strip seals were proposed. All of the seals used in the twelve bridges that had the most serious failures were in concrete girder bridges. Experimental results show that for a majority of these serious failures, the joint opening at 0° F predicted by the Iowa DOT design equations, the joint opening at 0° F extrapolated from the experimental data, or both, are larger than the movement rating of the strip seal specified on the bridge plans. Other likely causes of premature failures of seals in the twelve bridges include debris and ice in the seal cavity, a large skew and the corresponding decrease in the movement rating of the seal, improper installation, and improper setting of the initial gap.

Field Evaluation of Timber Preservation Treatments for Highway Applications Final Report, December 2007

Timber material repair and replacement cost for timber bridges is a considerable expense to highway agencies in Iowa, especially to county road departments. To address these needs, the objectives of this investigation was to study the field effectiveness of various treatment alternatives used on Iowa roadway projects and to determine if the current specifications and testing are adequate for providing proper wood preservation. To satisfy the research needs, the project scope involved a literature review, identification of metrics, questionnaire survey of Iowa counties, onsite inspections, and a review of current specifications and testing procedures. Based on the preservative information obtained, the following general conclusions were made: Copper naphthenate is recommended as the plant-applied preservative treatment for timber bridges. Best Management Practices should be followed to ensure quality treatment of timber materials. Bridge maintenance programs need to be developed and implemented. The Iowa Department of Transportation specifications for preservative treatment are the regulating specification for bridges constructed with state or federal funding in Iowa and are also recommended for all other bridges.

Road Safety Audit for the Intersection of US 59 and IA 9 in Osceola County, Iowa Final Report, March 2012

The Iowa Department of Transportation (DOT) requested a road safety audit (RSA) of the US 59/IA 9 intersection in northwestern Iowa, just south of the Minnesota border, to assess intersection environmental issues and crash history and recommend appropriate mitigation to address the identified safety issues at the intersection. Although the number of crashes at the location has not been significantly higher than the statewide average for similar intersections, the severity of these crashes has been of concern. This RSA was unique in that it included intersection video observation and recorded traffic conflict data analysis, along with the daylight and nighttime field reviews. This report outlines the findings and recommendations of the RSA team for addressing the safety concerns at this intersection.

Report to the Governor and General Assembly on Voluntary Employer-Sponsored Health Care Coverage Demonstration Project-Non-licensed Direct Care Workers, December 2008

Iowa faces a growing crisis in providing an adequate number of direct care workers for its again population. Direct care workers caring for the aging and disabled population are among those in our work force with the lowest wages and lack of access to health insurance. A survey of direct care workers conducted by the Iowa Caregivers Association in June of 2066 indicated that benefits ranked second only to wages in the reasons for job-hoping. A study of the direct care workforce in Vermont healthy insurance, ranked second only to wages, as important to attracting and keeping direct care workers.

Road Use Tax Fund Efficiency Report Savings Status, December 31,

Develop, in conjunction with the regional planning affiliations and metropolitan planning organizations and other stakeholder groups, a process to exchange STP federal funds for Primary Highway System funds for the purpose of reducing the number of small projects that have to meet onerous federal requirements. In order to implement this recommendation, legislative action is required to eliminate the restriction on using Primary Road Fund revenue on local jurisdiction roadways in exchange for a portion of their federal STP funding. This past session, Iowa DOT worked with legislators to introduce a bill in both the House and the Senate to eliminate this Code restriction. Bills were discussed at the subcommittee level in both the House and Senate but did not proceed because of the need to have further discussions with impacted parties. Prior to next session, discussions will occur amongst all impacted parties to reach consensus on how this recommendation could be implemented. With that consensus in place prior to next session, it is anticipated that the bills can be reintroduced next session.

Individual Project Summaries, 2011

Farms to Fuel project will demonstrate technology to produce alternative renewable energy by combining cattle manure with organic industrial waste products in an anaerobic digester. The digester produces methane gas which fires an engine set to generate base load electricity. This would create environmental benefits by turning crop, livestock, and industrial waste into renewable energy in a sustainable and profitable way. Other benefits of the project include the production of a fertilizer that is more readily applicable to crops than in its raw form.

Iowa Power Fund Board Project Report Update, July 29, 2009

Amana Farms is using an anaerobic digestion, which is a two-stage digester that converts manure and other organic wastes into three valuable by-products: 1) Biogas – to fuel an engine/generator set to create electricity; 2) Biosolids - used as a livestock bedding material or as a soil amendment; 3) Liquid stream - will be applied as a low-odor fertilizer to growing crops. (see Business Plan appendix H) The methane biogas will be collected from the two stages of the anaerobic digestion vessel and used for fuel in the combined heat and power engine/generator sets. The engine/generator sets are natural gasfueled reciprocating engines modified to burn biogas. The electricity produced by the engine/generator sets will be used to offset on-farm power consumption and the excess power will be sold directly to Amana Society Service Company as a source of green power. The waste heat, in the form of hot water, will be collected from both the engine jacket liquid cooling system and from the engine exhaust (air) system. Approximately 30 to 60% of this waste heat will be used to heat the digester. The remaining waste heat will be used to heat other farm buildings and may provide heat for future use for drying corn or biosolids. The digester effluent will be pumped from the effluent pit at the end of the anaerobic digestion vessel to a manure solids separator. The mechanical manure separator will separate the effluent digested waste stream into solid and liquid fractions. The solids will be dewatered to approximately a 35% solid material. Some of the separated solids will be used by the farm for a livestock bedding replacement. The remaining separated solids may be sold to other farms for livestock bedding purposes or sold to after-markets, such as nurseries and composters for soil amendment material. The liquid from the manure separator, now with the majority of the large solids removed, will be pumped into the farm’s storage lagoon. A significant advantage of the effluent from the anaerobic digestion treatment process is that the viscosity of the effluent is such that the liquid effluent can now be pumped through an irrigation nozzle for field spreading.

Iowa Power Fund Board Project Report Update, July 29, 2009

Climate refers to the long-term course or condition of weather, usually over a time scale of decades and longer. It has been documented that our global climate is changing (IPCC 2007, Copenhagen Diagnosis 2009), and Iowa is no exception. In Iowa, statistically significant changes in our precipitation, streamflow, nighttime minimum temperatures, winter average temperatures, and dewpoint humidity readings have occurred during the past few decades. Iowans are already living with warmer winters, longer growing seasons, warmer nights, higher dew-point temperatures, increased humidity, greater annual streamflows, and more frequent severe precipitation events (Fig. 1-1) than were prevalent during the past 50 years. Some of the impacts of these changes could be construed as positive, and some are negative, particularly the tendency for greater precipitation events and flooding. In the near-term, we may expect these trends to continue as long as climate change is prolonged and exacerbated by increasing greenhouse gas emissions globally from the use of fossil fuels and fertilizers, the clearing of land, and agricultural and industrial emissions. This report documents the impacts of changing climate on Iowa during the past 50 years. It seeks to answer the question, “What are the impacts of climate change in Iowa that have been observed already?” And, “What are the effects on public health, our flora and fauna, agriculture, and the general economy of Iowa?”

End of Project Report to the Iowa Power Fund, October 31, 2008

The 2008 Biobased Industry Outlook Conference was held September 7-10 on the Iowa State University campus. Over 750 people attended the plenary sessions on the morning of September 8th; 580 people registered for the full conference. Sponsorships: $92,500 in sponsorships in addition to the IPF was secured for the conference (considered “match” to the IPF grant). Including the $11,250 IPF sponsorship ($12,500 minus overhead charges of $1,250), the total amount contributed for conference sponsorships was $103,750. A list of sponsors and the amount of sponsorship is listed in Appendix A. Sponsorship funds received from the Iowa Power Fund were used for supplies and materials. Please see Appendix B which documents the transfer of IPF grant funds internally at ISU and their use.

Visualization Resources for Iowa State University and the Iowa DOT: An Automated Design Model to Simulator Converter, November 2012

This project developed an automatic conversion software tool that takes input a from an Iowa Department of Transportation (DOT) MicroStation three-dimensional (3D) design file and converts it into a form that can be used by the University of Iowa’s National Advanced Driving Simulator (NADS) MiniSim. Once imported into the simulator, the new roadway has the identical geometric design features as in the Iowa DOT design file. The base roadway appears as a wireframe in the simulator software. Through additional software tools, textures and shading can be applied to the roadway surface and surrounding terrain to produce the visual appearance of an actual road. This tool enables Iowa DOT engineers to work with the universities to create drivable versions of prospective roadway designs. By driving the designs in the simulator, problems can be identified early in the design process. The simulated drives can also be used for public outreach and human factors driving research.