Biosecurity and Infectious Animal Disease, November 2005

The spatial dimension of agricultural production is important when a communicable disease enters a region. This paper considers two sorts of biosecurity risk that producers can seek to protect against. One concerns the risk of spread: that neighboring producers do not take due care in protecting against being infected by a disease already in the region. In this case, producer efforts substitute with those of near neighbors. For representative spatial production structures, we characterize Nash equilibrium protection levels and show how spatial production structure matters. The other sort of risk concerns entry: that producers do not take due care in preventing the disease from entering the region. In this case, producer heterogeneity has subtle effects on welfare loss due to strategic behavior. Efforts by producers complement, suggesting that interfarm communication will help to redress the problem.

2010- 2014 Iowa Transportation Improvement Program

The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state’s transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. A major component of the 2010-2014 Program is the full integration of funding allocated to the Iowa DOT from the American Recovery and Reinvestment Act of 2009 (Recovery Act). To date, the Recovery Act has provided over $400 million of additional federal funding for transportation in Iowa, including funding that is allocated to local governments and entities. Recovery Act funding will result in a record year for transportation construction in Iowa and the creation and retention of jobs. Opportunities for additionalRecovery Act transportation funding remain and will be pursued as they becomeavailable. While Recovery Act funding will make a one-time significant impact in addressing Iowa’s backlog of needs, it is important to note that there remains a large shortfall in sustained annual transportation investment to meet Iowa’s current and future critical transportation needs. In recognition of this shortfall, Governor Culver introduced and the legislature passed an I-JOBS proposal. I-JOBS will result in an additional $50 million of state funding to reduce structurally deficient and functionally obsolete bridges on the primary road system and approximately $10 million in funding for other modes of transportation including $3 million of new funding to support the expansion of passenger rail service in Iowa. I-JOBS, and the continuing gradual increase in funding due to TIME-21, will complement and extend the benefits of Recovery Act funding and set the stage for addressing the shortfall in annual funding in the next few years. Iowa’s transportation system is multi-modal; therefore, the Program encompasses investments in aviation, transit, railroads, trails, and highways. A major component of the Program is the highway section. The FY2010-2014 highway section is financially balanced and was developed to achieve several objectives. The Commission’s primary highway investment objective is stewardship (i.e. safety, maintenance and preservation) of Iowa’s existing highway system. The highway section includes an annual average of $104 million for preserving the interstate system; an annual average of $78 million for non-interstate pavement preservation; an annual average of $36 million for non-interstate bridges; and an annual average of $14 million for safety projects. Another objective is to maintain the scheduled completion of interstate and non-interstate capacity and economic development projects that were identified in the previous Program and this Program does so. The final Commission objective is to further address capacity and economic development needs and the Commission has done so by adding several such projects to the Program. Construction improvements are partially funded through the current federal transportation act, Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). The act will expire September 30, 2009. With the expiration of SAFETEA-LU, there is significant uncertainty in the forecast of federal revenues in the out-years of this Program. The Commission and Iowa DOT will monitor federal actions closely and make adjustments to the Program as necessary. The Iowa DOT and Commission appreciate the public’s involvement in the state’s transportation planning process. Comments received personally, by letter, or through participation in the Commission’s regular meetings or public input meetings held around the state each year are invaluable in providing guidance for the future of Iowa’s transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change. You are invited to visit the Iowa DOT’s Web site at iowadot.gov for additional and regular updates about the department’s programs and activities.

your Ticket to Safety: Bloodborne Pathogen Awareness, January 16, 2001

This handbook has been prepared to complement the informational videotape, Your Ticket to Safety: Bloodborne Pathogen Awareness for Transit Professionals. The handbook also provides a personal and ready reference regarding bloodborne pathogens for public transit system personnel, including managers, drivers, mechanics, other employees and service providers. Additional copies of this handbook and the videotape are available through the Office of Public Transit.

Evaluation of Variable Advisory Speed Limits in Work Zones, TPF-5(081), 2013

Variable advisory speed limit (VASL) systems could be effective at both urban and rural work zones, at both uncongested and congested sites. At uncongested urban work zones, the average speeds with VASL were lower than without VASL. But the standard deviation of speeds with VASL was higher. The increase in standard deviation may be due to the advisory nature of VASL. The speed limit compliance with VASL was about eight times greater than without VASL. At the congested sites, the VASL were effective in making drivers slow down gradually as they approached the work zone, reducing any sudden changes in speeds. Mobility-wise the use of VASL resulted in a decrease in average queue length, throughput, number of stops, and an increase in travel time. Several surrogate safety measures also demonstrated the benefits of VASL in congested work zones. VASL deployments in rural work zones resulted in reductions in mean speed, speed variance, and 85th percentile speeds downstream of the VASL sign. The study makes the following recommendations based on the case studies investigated: 1. The use of VASL is recommended for uncongested work zones to achieve better speed compliance and lower speeds. Greater enforcement of regulatory speed limits could help to decrease the standard deviation in speeds; 2. The use of VASL to complement the static speed limits in rural work zones is beneficial even if the VASL is only used to display the static speed limits. It leads to safer traffic conditions by encouraging traffic to slow down gradually and by reminding traffic of the reduced speed limit. A well-designed VASL algorithm, like the P5 algorithm developed in this study, can significantly improve the mobility and safety conditions in congested work zones. The use of simulation is recommended for optimizing the VASL algorithms before field deployment.

Response of Iowa Pavements to a Tracked Agricultural Vehicle, HR-1075, Phase II, 2000

The overall objective of the work summarized in this report and in the interim report was to study the effects of targeted implement-of-husbandry loads. This report is to complement phase I of this work, which was summarized in the interim report, entitled Response of Iowa Pavements to Heavy Agricultural Loads (December 1999). The response of newly constructed Portland cement concrete (PCC) and asphalt cement concrete (ACC) pavements under semitruck, single-axle single-tire grain wagon, single-axle dual-tire grain wagon, tandem and tridem tank wagons were summarized in the interim report. Phase II of this project, presented herein, was to complete the study in terms of how tracked agricultural vehicles relate to the reference 20,000-pound single-axle semi-truck. In this report the response of these two pavements under a tracked grain wagon is documented.

Drying Shrinkage in P.C. Concrete, MLR-89-5, 1990

Crack formation has been a problem on some recently constructed bridges in Iowa. Drying shrinkage has been considered a contributing factor in that cracking. The study was undertaken to evaluate some of those material properties that contribute to the magnitude of drying shrinkage. Cement content, cement composition, fly ash and retarding admixture were the factors studied. Concrete prisms were cast for seven mixes and, after curing, were exposed to 100 deg F heat at ambient humidity for 280 days. The following were observed from the testing: (1) Higher C3A content cement concrete produced larger shrinkage; (2) Use of fly ash increased shrinkage; (3) Use of retarder increased shrinkage; and (4) Lowering the cement content reduced the shrinkage.

08012-008 Lake Morris Final Report

Lake Morris is the larger of two lakes which serve as the municipal water supply for the City of Chariton, Iowa. As a site for fishing and boating, it also serves as a significant recreational resource for area residents. Its ability to sustain these uses has been significantly impaired by long-term and ongoing accumulation of sediment and sediment-borne nutrients from both public and private land within the watershed. This accumulation has resulted in reduced water depth, reduced water-holding capacity, reduced quality of the fishery, increased water turbidity, increased growth of undesirable algae, and increased cost of treating the water for municipal uses. Water quality projects undertaken in the past, notably the Lucas Lakes Project of the 1990s, made important progress in reducing sedimentation from privately-owned land higher in the watershed, but paid little attention to land owned by the City of Chariton immediately surrounding the lakes. A recent reassessment of gully erosion within the watershed shows serious, ongoing erosion on that City-owned land. This project proposes a two-part approach to improving the water quality in Lake Morris. First, we propose that a complement of five SolarBee water circulation devices be installed in Lake Morris to provide near-term and continuing improvements in water quality, by inhibiting cyanobacterial growth and thereby removing the need for treatment of the lakes with copper sulfate. Second, we propose the installation of erosion-control structures on primarily City-owned land surrounding the lake, to provide a major reduction in ongoing sedimentation.

Evaluation of Mini Slump Cone Test, MLR-97-01, 2000

Early stiffening of cement has been noted as contributing to workability problems with concrete placed in the field. Early stiffening, normally attributed to cements whose gypsum is reduced to hemi⋅hydrate or anhydrate because of high finish mill temperatures, is referred to as false setting. Stiffening attributed to uncontrolled reaction of C3A is referred to as flash set. False setting may be overcame by extended mix period, while flash setting is usually more serious and workability is usually diminished with extended mixing. ASTM C 359 has been used to detect early stiffening with mixed results. The mini slump cone test was developed by Construction Technology Laboratories (CTL), Inc., as an alternative method of determining early stiffening. This research examined the mini slump cone test procedure to determine the repeatability of the results obtained from two different testing procedures, effect of w/c ratio, lifting rate of the cone, and accuracy of the test using a standard sample.

Evaluation of PCC Specification Changes Impact on Durability: 1992 - 1997 Core Study, MLR-98-06, 2005

In 1990, early distress had shown up on US 20 in Hamilton/Webster counties, three years after paving. Since that time, over a dozen more projects, constructed between 1984 and 1994, have been found to exhibit similar early distress. Several changes to the concrete and Portland cement specifications occurred in 1994 and 1996. This study was undertaken to investigate in place concrete pavements before and after specification changes were implemented. The objective of this research is to evaluate the impact of Portland cement and concrete specification changes made in 1994 and 1996 on PCC durability. Cores were obtained in 1998 and 2003 from projects constructed in 1992, before specification changes, and 1997 after specification changes. The following is a brief summary of the conclusions: 1. The pavements in the study constructed under the new specifications are performing much better after 5 years of service than the pavements constructed under the old specifications. 2. According to ISU, micro-cracking is evident in all concrete that has been in service, due to thermal stresses and loading stresses. Also, the low vacuum SEM will desiccate the concrete enough to cause micro-cracking. The SEM should not be used as a tool to indicate micro-cracking. 3. Use of Type II cement (C3A <8%) and a 3.0% SO3 limit does not completely eliminate ettringite infilling in air voids, as indicated in the bottom of the 1997 cores. 4. In areas of high moisture (bottom of the core), infilling is present in most of the 1997 cores. 5. Low air content and high spacing factor in the top of 1992 cores apparently causes F/T cycling cracking and then increased moisture paths from cracking causes infilling. 6. Use of ground granulated blast furnace slag (GGBFS) and fly ash reduces ettringite infilling either by diluting the aluminate (C3A) or lowering permeability, which slows ingress of moisture. 7. The specification changes that made the biggest impact on pavement durability are the limits on vibration and increase in air content in September 1994. 8. Investigations of cores from pavements placed in 2002 and 2003 indicate improved air contents and spacing factors. In-place air content and spacing factors should be monitored to determine if appropriate air void parameters are being met.