An Analysis of the Link between Ethanol, Energy, and Crop Markets, November 2006

This study analyzes the impact of price shocks in three input and output markets critical to ethanol: gasoline, corn, and sugar. We investigate the impact of these shocks on ethanol and related agricultural markets in the United States and Brazil. We find that the composition of a country’s vehicle fleet determines the direction of the response of ethanol consumption to changes in the gasoline price. We also find that a change in feedstock costs affects the profitability of ethanol producers and the domestic ethanol price. In Brazil, where two commodities compete for sugarcane, changes in the sugar market affect the competing ethanol market.

Taking Chances on Integrity: An Investigation of the Iowa Lottery

The Iowa Lottery has failed to adequately protect its customers from fraud and theft by retailers. That is the key conclusion of the Iowa Citizens’ Aide/Ombudsman in a critical report released today. The 210-page report, which makes 60 recommendations to the Lottery, is the culmination of a year-and-a-half-long investigation into how the Lottery polices and prevents retailer fraud and theft. In general, the Ombudsman found that the Lottery has maintained a weak, reactive enforcement system that fails to detect retailer dishonesty independently of customer complaints. This means that there likely have been instances of fraud – possibly largescale fraud – that have gone undetected. The Ombudsman’s examination marks the first time the Iowa Lottery’s investigative files have been audited by an outside authority. It also appears to be the first full-scale investigation of its kind in the United States.

Walking a Fine Line: An Investigation of the Monticello Mayor and City Council, July 5, 2011

Iowa Citizen Aide - Ombudsman Office received a complaint on February 22, 2010, concerning the manner in which the mayor and several city council members for the City of Monticello (City) attempted to remove the city administrator from his position. It was alleged that the mayor and at least one council member went to the homes of other council members and sought their signatures on a letter of offer requesting the city administrator to resign or face a vote to terminate his employment. We were asked to investigate whether this action complied with Iowa’s Open Meetings Law.

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.

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.

An illustration of the ALLOC 6B location-allocation analysis system, 1984

The programs included in this Discussion Paper no. 17 are Distance, Unravel, Retrench and Alloc 6B that deal with location-allocation analyses first published in 1973 by the Department of Geography, The University of Iowa.

An Evaluation of the Roto-Mill Profiler on Concrete Pavements in Iowa, MLR-76-1, 1976

A new machine, the ROTO-MILL Profiler, became available in early 1976. This machine, manufactured by CMI Corporation of Oklahoma City, Oklahoma provides pavement surface Scarification at a much higher production rate than was previously possible. Iowa had the opportunity to observe and evaluate this machine on two separate sections of primary portland cement concrete pavement in October, 1976. The marked improvement in the profile index and the skid resistance indicates this machine may be considered a viable method for improving rideability and skid resistance of a roadway that is otherwise reasonably sound.

An Evaluation of the Troxler 3241-B Nuclear Asphalt Gauge, MLR-85-11, 1986

The Troxler 3241-B Asphalt Content Gauge is intended for rapidly determining the bitumen content of bituminous paving mixtures. A 300 Millicurie Americuium 241: Beryllium source emitts neutrons which are affected by the hydrogen in the mix. The affected neutrons are detected by Helium 3 detectors, counted and computed into a percentage bitumen of the asphalt mix. The current methods of determining the bitumen content of bituminous paving mixtures requires the use of potentially hazardous chemicals and several hours of testing time. When extracted aggregates are not needed, determination of the bitumen content of a paving mixture by the nuclear method may be easier, quicker and potentially safer. The objective of the project is to study the accuracy of the Troxler 3241-B Nuclear Asphalt Content Gauge in measuring the asphalt cement (AC) content of asphalt concrete mixtures produced with different asphalt cements and different aggregates.

An Evaluation of the Consolidation Monitoring Device, HR-1013, 1978

The Iowa Department of Transportation research project HR-1013 is the evaluation of a prototype continuous monitoring nuclear density unit. The Unit, the Consolidation Monitoring Device (CMD), mounts on the rear of a slip-form paver and measures the density of the concrete while still in the plastic state. The evaluation performed determined the usefulness, accuracy, precision and reproducibility of the unit. The CMD was calibrated and tested in the laboratory for one week before field evaluation. The field evaluation consisted of monitoring at least 5 miles of paving and then correlating the CMD data with two conventional density methods. The two supplemental methods were density measurement with a Troxler nuclear gauge and densities obtained from core samples.

An Evaluation of the Second Generation Consolidation Monitoring Device, HR-1013, 1984

The objective was to evaluate the usefulness, accuracy, precision, and reproducibility of the second generation CMD for PC concrete under production conditions.

An Investigation of the Chemical Method of Determining the Cement Content of Hardened Concrete, MLR-71-01 and R-248, 1971

The Iowa State Highway Commission Laboratory is called upon to determine the cement content of hardened concrete when field problems relating to batch weights are encountered. The standard test for determining the cement content is ASTM C-85. An investigation of this method by the New Jersey State Highway Department involving duplicate samples and four cooperating laboratories produced very erratic results, however, the results obtained by this method have not been directly compared to known cement contents of concrete made with various cements and various aggregates used in Iowa.

An Estimate of the Cost to Resurface Pavements and Bridges Damaged by Studded Tires, 1972

This report contains an estimate of the cost of highway resurfacing necessitated by damage from studded tires. The total is $95,620,000 for the twenty-five years from 1971 to 1996. This total includes $51,937,000 to resurface pavements and bridges on Interstate routes and $43,683,000 for other Primary highways. The estimate for Interstate routes includes those sections now open to traffic and those planned for completion by November 1974. The estimate for other Primary routes includes rural and municipal sections open to traffic as of November 1970. The estimate was prepared by computing the cost of expected pavement and bridge resurfacing costs for the twenty-five year period assuming continued use of studded tires, then subtracting from this the expected resurfacing ) cost for the same period assuming that the use of' studded tires is prohibited. The total figure, $95,620,000, should be regarded as a conservative estimate of the cost which may be avoided by prohibiting the use of studded tires in Iowa. The conservative nature of the estimate may be demonstrated by the following examples of the guidelines used iri its preparation. 1. Only mainline pavements were included in the cost estimate for the Interstate routes. The connecting loops, exit ramps and entrance ramps at Interstate interchanges contain many additional miles of pavement subject to wear by studded tires. This pavement was omitted from the estimate because reliable ' information about the rate of pavement wear at such locations is not available. As a result, the Interstate resurfacing costs are underestimated. 2. Several other costs were also omitted from the estimate because of a lack of sufficient information. These include the cost of repairing damage caused by studded tires to city streets other than those designated as Primary routes, the damage to pavements and bridges on the more-heavily travelled Secondary roads, and the damage to pavement traffic markings on all highway systems. Experience indicates that portland cement concrete pavements in Iowa have a normal service life of twenty-five years before resurfacing becomes necessary. The service life for asphalt pavements is thirteen years. In making this cost estimate, the need for resurfacing was attributed to wear from studded tires only when the normal service life of the pavement was shortened by that wear. Consequently, this cost estimate does not account for the reduced safety and convenience to Iowa motorists during the time when pavement wear caused by studded tires is significant but less than the critical amount.

An Evaluation of the Calderon Test, HR-80, 1963

As a result of Chang's studies, Calderon's developments, and the need for a new test procedure to determine specific physical properties of an asphalt concrete, the Iowa Highway Research Board sponsored a research project to investigate the correlation of results of the Calderon Test with the Iowa Stability Test and the Marshall and Hveem stability tests using Iowa Type A asphaltic concrete. The project was assigned to the Bituminous. Research Laboratory of Iowa State University as Project HR 80, the. Iowa Highway Research Board, and Project 442-S of the Engineering Experiment Station.