Dowel Bar Optimization: Phases I and II, October 2001

America’s roadways are in serious need of repair. According to the American Society of Civil Engineers (ASCE), one-third of the nation’s roads are in poor or mediocre condition (1). ASCE has estimated that under these circumstances American drivers will sacrifice $5.8 billion and as many as 13,800 fatalities a year from 1999 to 2001 ( 1). A large factor in the deterioration of these roads is a result of how well the steel reinforcement transfers loads across the concrete slabs. Fabricating this reinforcement using a shape conducive to transferring these loads will help to aid in minimizing roadway damage. Load transfer within a series of concrete slabs takes place across the joints. For a typical concrete paved road, these joints are approximately 1/8-inch gaps between two adjacent slabs. Dowel bars are located at these joints and used to transfer load from one slab to its adjacent slabs. As long as the dowel bar is completely surrounded by concrete no problems will occur. However, when the hole starts to oblong a void space is created and difficulties can arise. This void space is formed due to a stress concentration where the dowel contacts the concrete. Over time, the repeated process of traffic traveling over the joint crushes the concrete surrounding the dowel bar and causes a void in the concrete. This void inhibits the dowel’s ability to effectively transfer load across the joint. Furthermore, this void gives water and other particles a place to collect that will eventually corrode and potentially bind or lock the joint so that no thermal expansion is allowed. Once there is no longer load transferred across the joint, the load is transferred to the foundation and differential settlement of the adjacent slabs will occur.

Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements, September 2004

The chemistry of today’s concrete mixture designs is complicated by many variables, including multiple sources of aggregate and cements and a plethora of sometimes incompatible mineral and chemical admixtures. Concrete paving has undergone significant changes in recent years as new materials have been introduced into concrete mixtures. Supplementary cementitious materials such as fly ash and ground granulated blast furnace slag are now regularly used. In addition, many new admixtures that were not even available a few years ago now have widespread usage. Adding to the complexity are construction variables such as weather, mix delivery times, finishing practices, and pavement opening schedules. Mixture materials, mix design, and pavement construction are not isolated steps in the concrete paving process. Each affects and is affected by the other in ways that determine overall pavement quality and long-term performance. Equipment and procedures commonly used to test concrete materials and concrete pavements have not changed in decades, leaving serious gaps in our ability to understand and control the factors that determine concrete durability. The concrete paving community needs tests that will adequately characterize the materials, predict interactions, and monitor the properties of the concrete.

Annual Report of Highway Division Highway Research and Development in Iowa for the Fiscal Year ending June 30, 2005

The Highway Division of the Iowa Department of Transportation engages in research and development for two reasons: first, to find workable solutions to the many problems that require more than ordinary, routine investigation; second, to identify and implement improved engineering and management practices. This report, entitled Highway Division Highway Research and Development in Iowa, is submitted in compliance with Sections 310.36 and 312.3A, Code of Iowa, which direct the submission of a report of the Secondary Road Research Fund and the Street Research Fund respectively. It is a report of the status of research and development projects, which were in progress on June 30, 2005; it is also a report on projects completed during the fiscal year beginning July 1, 2004, and ending June 30, 2005. Detailed information on each of the research and development projects mentioned in this report is available in the Research and Technology Bureau in the Highway Division of the Iowa Department of Transportation.

Local Roads Maintenance Workers’ Manual, June 2006

This manual describes best roadway maintenance practices for Iowa's local roads and streets, from the center line to shoulders, ditches, and drainage, with chapters on public relations, bridge maintenance, and snow and ice control. Each chapter contains safety tips, information(as appropriate) on managing quality control, and a list of references for further information.

Evaluation of U.S. and European Concrete Pavement Noise Reduction Methods, July 2006

Highway noise is one of the most pressing of the surface characteristics issues facing the concrete paving industry. This is particularly true in urban areas, where not only is there a higher population density near major thoroughfares, but also a greater volume of commuter traffic (Sandberg and Ejsmont 2002; van Keulen 2004). To help address this issue, the National Concrete Pavement Technology Center (CP Tech Center) at Iowa State University (ISU), Federal Highway Administration (FHWA), American Concrete Pavement Association (ACPA), and other organizations have partnered to conduct a multi-part, seven-year Concrete Pavement Surface Characteristics Project. This document contains the results of Part 1, Task 2, of the ISU-FHWA project, addressing the noise issue by evaluating conventional and innovative concrete pavement noise reduction methods. The first objective of this task was to determine what if any concrete surface textures currently constructed in the United States or Europe were considered quiet, had long-term friction characteristics, could be consistently built, and were cost effective. Any specifications of such concrete textures would be included in this report. The second objective was to determine whether any promising new concrete pavement surfaces to control tire-pavement noise and friction were in the development stage and, if so, what further research was necessary. The final objective was to identify measurement techniques used in the evaluation.

Study of Iowa's Current Road Use Tax Funds (RUTF) and Future Road Maintenance and Construction Needs, 2006

The 81st General Assembly of the Iowa Legislature, in Section 85 of House File 868, required the Iowa Department of Transportation (DOT) to conduct a study of current Road Use Tax Fund (RUTF)revenues, and projected roadway construction and maintenance needs.

Annual report of the Iowa Highway Research Board Research and Development Activities FY 2006

The Highway Division of the Iowa Department of Transportation engages in research and development for two reasons: first, to find workable solutions to the many problems that require more than ordinary, routine investigation; and second, to identify and implement improved engineering and management practices. This report is submitted in compliance with Sections 310.36 and 312.3A, Code of Iowa, which direct the submission of a report of the Secondary Road Research Fund and the Street Research Fund, respectively. It is a report of the status of research and development projects, which were in progress on June 30, 2006; it is also a report on projects completed during the fiscal year beginning July 1, 2005, and ending June 30, 2006.

Study of Iowa’s Current Road Use Tax Funds (RUTF) and Future Road Maintenance and Construction Needs, 2006

The 81st General Assembly of the Iowa legislature, in Section 85 of House File 868, required the Iowa Department of Transportation (Iowa DOT) to conduct a study of current Road Use Tax Fund (RUTF) revenues, and projected roadway construction and maintenance needs. With input from Iowa’s cities, counties and other interested groups, the Iowa DOT completed this report for submittal to the legislature.

Study of Iowa’s Current Road Use Tax Funds (RUTF) and Future Road Maintenance and Construction Needs, 2006

The 81st General Assembly of the Iowa legislature, in Section 85 of House File 868, required the Iowa Department of Transportation (Iowa DOT) to conduct a study of current Road Use Tax Fund (RUTF) revenues, and projected roadway construction and maintenance needs.

Lane Closure Policy Development, Enforcement, and Exceptions: A Survey of Seven State Transportation Agencies, February 2007

Traffic volume increases and an aging infrastructure create the need for reconstruction, rehabilitation, and maintenance of existing facilities. As more motorists feel that delays should be minimal during highway renewal projects, lane closures that reduce capacity through the work zone should not create unreasonable delays. In order to facilitate the determination of when a lane closure is permitted during the day, some state transportation agencies (STAs) have developed lane closure policies, or strategies, that they use as guidance in determining daily permitted lane closure times. Permitted lane closure times define what times of the day, week, or season a lane closure is allowed on a facility and at a specific location or segment. This research addresses the lane closure policies of several STAs that were reputed to have good lane closures policies or strategies and that were selected by the project advisory committee for further research.

Iowa Department of Transportation; Equipment and Vehicle Purchase Report for Fiscal Year 2007

This is the Iowa Department of Transportation's Equipment and Vehicle Purchase Report for Fiscal Year 2007 as required by Iowa Code section 307.47. The report is sorted by our accounting object codes.

Annual Report of Iowa Highway Research Board Research and Development Activities FY 08

RESEARCH AND DEVELOPMENT The Highway Division of the Iowa Department of Transportation (Iowa DOT) engages in research and development for two reasons: first, to find workable solutions to the many problems that require more than ordinary, routine investigation; second, to identify and implement improved engineering and management practices. This report, entitled "Iowa Highway Research Board Research and Development Activities FY2008" is submitted in compliance with Sections 310.36 and 3 I2.3A, Code of Iowa, which direct the submission of a report of the Secondary Road Research Fund and the Street Research Fund respectively. It is a report of the status of research and development projects in progress on June 30, 2008; it is also a report on projects completed during the fiscal year beginning July 1, 2007, and ending June 30, 2008. Detailed information on each of the research and development projects mentioned in this report is available in the Research and Technology Bureau in the Highway Division of the Iowa Department of Transportation. IOWA HIGHWAY RESEARCH BOARD In developing a progressive, continuing and coordinated program of research and development, the Highway Division is assisted by the Iowa Highway Research Board. This advisory group was established in 1949 by the Iowa State Highway Commission to respond to the research denoted in Section 310.36 of the Code of Iowa and now is denoted by 312.3A. The Research Board consists of 15 regular members: seven Iowa county engineers, four Iowa DOT engineers, one representative from Iowa State University, one from The University of Iowa, and two engineers employed by Iowa municipalities. Each regular member may have an alternate who will serve at the request of the regular member. The regular members and their alternates are appointed for a three-year term. The membership of the Research Board as of June 30, 2008, is listed in Table I. The Research Board held nine regular meetings during the period ofJuly 1, 2007, to June 30, 2008. Suggestions for research and development were reviewed at these meetings and recommendations were made by the Board.

Investing in Iowa’s Highways, May 29, 2009

The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) develop Iowa’s Five-Year Transportation Improvement Program (Five-Year Program) to inform Iowans of planned investments in our state’s multi-modal transportation system. The Five-Year Program is typically updated and approved each year in June. The Five-Year Program encompasses investments in aviation, transit, railroads, trails, and highways. This brochure describes the programming process used by the Commission and Iowa DOT to develop the highway section of the Five-Year Program.

Iowa’s Railroads and You, July 28, 2004

Like most motorists, you want your trips to go as quickly and smoothly as possible. Things like having to wait at a railroad crossing while the train crosses, or having to slow for a rough railroad crossing may seem like an inconvenience. But, when you look at the overall picture, you will find there are many things that affect your trips: heavy traffic, including large trucks, on the interstates; congestion on urban freeways; a lot of pedestrian traffic at crosswalks; a bus stopped on the street while passengers are boarding or exiting; slow-moving farm equipment or bicyclists on a rural road; or any number of other disruptions. The reality is that Iowa’s transportation system is extremely complex. Iowa has many diverse transportation users and all types of vehicles traveling at differing speeds.

Relocation Assistance and Advisory Services, March 24, 2009

This brochure provides general information about relocation assistance provided by the Iowa Department of Transportation (DOT) for those individuals who may be required to move as a result of a highway project. It is not intended to be a legal document that comprehensively explains every right or obligation you have as established by Chapter 316, Code of Iowa; Federal Public Laws 91-646 and 100-17; and 49 CFR. Your relocation adviser will provide the assistance you need to successfully relocate to a suitable replacement property. Your first contact with your relocation adviser will usually occur during the early stages of the appraisal process, and he or she will continue to work with you until you have moved and become established at a new location. Do not hesitate to ask questions so you are sure you understand the process, your rights and the benefits available to you. Please let your DOT relocation adviser know your needs and preferences. If your relocation adviser is unable to help you with a specific problem or concern, he or she may know of another person or an organization that can help you. DO NOT MOVE UNTIL YOU HAVE CONTACTED YOUR DOT RELOCATION ADVISER. Only then will you be sure you are not jeopardizing your potential rights and benefits under this program. No person who lawfully occupies real property will be required by DOT to move without being notified in writing at least 90 days in advance.