Precast Concrete Panel Thickness for Epoxy-Coated Prestressing Strands, HR-353, Interim Report, 1994

A recommended minimum thickness for prestressed concrete (P/C) bridge deck panels containing 3/8-in. diameter, 270-ksi, low-relaxation, grit-impregnated, epoxy-coated prestressing strands is being evaluated by testing prototype panel specimens. As of January 1994, specimens from ten castings have been tested. The specimens in the first five castings were constructed to establish a preliminary minimum thickness for P/C panels. The specimens in the last five castings were constructed to 1) confirm the minimum panel thickness requirement, 2) measure the development length of epoxy-coated strands in specimens containing multiple strands, 3) measure the development length of uncoated strands in specimens containing multiple and single strands, 4) observe if concrete cracks form in thin panel specimens that have a raked top surface and are reinforced with welded wire fabric and either epoxy-coated or uncoated strands, 5) measure the transfer length for specimens containing a single uncoated strand, and 6) observe the seating characteristics of the grips used for uncoated strand and epoxy-coated strands. These tests have produced several initial findings. The preliminary recommended thickness for P/C panels containing grit-impregnated, epoxy-coated strands is 3 in. and the tentative development length for uncoated and coated multiple strands is approximately 45 in. and 24 in., respectively. Further tests will address confirmation of the recommended P/C panel thickness and establish the transfer and development lengths of single and multiple, uncoated and grit-impregnated epoxy-coated strands.

Iowa Highway Programs, Finances, and Progress, 1951

(a) Iowa has a total of 101,620 miles of rural roads, both primary and secondary. (b) On January 1, 1951, a total of 68,869 miles of these rural roads were surfaced - mostly with gravel and crushed stone. (c) Additional roads are being surfaced at the rate of 2676 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 26.0 per cent from property taxes, 63.5 per cent from road use taxes, 10.5 per cent from Federal aid. (f) Annual income under present laws, available for highway construction, is approximately For primary roads ----------------- $24,000,000 For secondary roads---------------- $41,967,000 (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued. (h) Unobligated available farm to market road funds are rapidly being placed under contract. (i) The letting of highway contracts is increasing rapidly. (j)- Iowa's highway program is estimated to cost $945,000,000 and will require twenty years to build. These are the highlights of Iowa's highway program. The details will follow in succeeding paragraphs.

Iowa Highway Programs, Finances, and Progress, 1952

(a) Iowa has a total of 101,620 miles of rural roads, both primary and secondary. (b) On January 1, 1952, a total of 71,493 miles of these rural roads were surfaced - mostly with gravel and crushed stone. (c) Additional roads are being surfaced at the rate of 2662 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 26.0 per cent from property taxes, 63.5 per cent from road use taxes, 10.5 per cent from Federal aid. (f) Annual income under present laws, available for highway construction, is approximately For primary roads------------------$23,000,000 For secondary roads---------------- 41,967,000 (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued. (h) The surplus of farm to market road funds created during and immediately following the War have now been placed under contract, with only a minimum working balance remaining in the fund. (i) Iowa's highway program was estimated to cost $945,000,000 and to require twenty years to build, by the 1948 Legislative Committee. This estimate would now have to be increased due to price increases and higher required standards. These are the highlights of Iowa's highway program. The details will follow in succeeding paragraphs.

Iowa Highway Program, Finances and Progress, 1954

(a) Iowa has a total of 101,451 miles of rural roads, both primary and secondary. (b) On January 1, l954, a total of 77,024 miles of these rural roads were surfaced - mostly with gravel and crushed stone. This is 5,53l miles greater than on January l, 1952. (c) Additional roads are being surfaced at the rate of 2766 miles per year. (d) Iowa's highway program provides for a surfaced road to every reasonably located rural home and a paved or other type of dustless surface on all primary roads. (e) Iowa's highway funds come 25.4 per cent from property taxes and special taxes......................................$29,708,546.67 63.7 per cent from road use taxes.......... 74,581,080.30 10.6 per cent from Federal Aid (1952 Act).. 12,424,000.00 0.3 per cent from miscellaneous receipts.. 287,922.86 ---- ------------- 100.0 $117,001,549.83 (f) Annual income under present laws, available for highway construction, is approximately, For primary roads $29,420,000.00 For secondary roads $44,328,000.00 In 19_3, $7,299,000 of secondary road construction funds was transferred to the maintenance fund. (g) Iowa's highway improvements are being paid for as built. No new bonds are being issued.

Iowa Highway Research Report No. 2, 1950-1951

During the fiscal year, July 1, 1950 to June 30, 1951, the Iowa State Highway Commission expanded its research program by adding to the work under way during the previous fiscal year, fifteen substantial projects recommended to the Commission by the Iowa Highway Research Board. The major portion of the projects under way in the previous fiscal year have been active in this fiscal year. All of the additional projects have gotten under way during this fiscal year. This year, as in the past, the work has been performed partly by Commission forces and partly by outside agencies such as the Institute of Hydraulic Research at Iowa City, the State University of Iowa, Iowa State College, the Iowa Geological Survey and the United States Geological Survey. The major portion of the fifteen new projects has been assigned to these outside agencies.

Primary Roads and Their Municipal Extensions, 1949

A discussion of several issues related to road construction, including budget, legislation, maintenance, and pending improvements.

Taxonomy of Institutional Issues that Act as Barriers to the Implementation of Pavement Management Systems, 1994

The benefits of pavement management system when fully implemented are well known and the history of successful implementation is rich. Implementation occurs, for purposes of this paper, when the pavement management system is the critical component for making pavement decisions. This paper addresses the issues that act as barriers to full implementation of pavement management systems. Institutional barriers, not technical and financial barriers, are more commonly responsible for a pavement management systems falling short of full implementation. The paper groups these institutional issues into a general taxonomy. In general, more effort needs to be put forth by highway agencies to overcome institutional issues. Most agencies approach pavement management as a technical process, but more commonly, institutional issues become more problematic and thus require more attention paid to institutional issues. The paper concludes by summarizing the implementation process being taken by the Iowa Department of Transportation. The process was designed to overcome institutional barriers and facilitate the complete and full implementation of their pavement management system.

Safety Assessment Tool for Construction Zone Work Phasing Plans, 2016

The Highway Safety Manual (HSM) is the compilation of national safety research that provides quantitative methods for analyzing highway safety. The HSM presents crash modification functions related to freeway work zone characteristics such as work zone duration and length. These crash modification functions were based on freeway work zones with high traffic volumes in California. When the HSM-referenced model was calibrated for Missouri, the value was 3.78, which is not ideal since it is significantly larger than 1. Therefore, new models were developed in this study using Missouri data to capture geographical, driver behavior, and other factors in the Midwest. Also, new models for expressway and rural two-lane work zones that barely were studied in the literature were developed. A large sample of 20,837 freeway, 8,993 expressway, and 64,476 rural two-lane work zones in Missouri was analyzed to derive 15 work zone crash prediction models. The most appropriate samples of 1,546 freeway, 1,189 expressway, and 6,095 rural two-lane work zones longer than 0.1 mile and with a duration of greater than 10 days were used to make eight, four, and three models, respectively. A challenging question for practitioners is always how to use crash prediction models to make the best estimation of work zone crash count. To solve this problem, a user-friendly software tool was developed in a spreadsheet format to predict work zone crashes based on work zone characteristics. This software selects the best model, estimates the work zone crashes by severity, and converts them to monetary values using standard crash estimates. This study also included a survey of departments of transportation (DOTs), Federal Highway Administration (FHWA) representatives, and contractors to assess the current state of the practice regarding work zone safety. The survey results indicate that many agencies look at work zone safety informally using engineering judgment. Respondents indicated that they would like a tool that could help them to balance work zone safety across projects by looking at crashes and user costs.

Pilot Study on Improving the Efficiency of Transportation Projects Using Laser Scanning, 2003

Laser scanning is a terrestrial laser-imaging system that creates highly accurate three-dimensional images of objects for use in standard computer-aided design software packages. This report describes results of a pilot study to investigate the use of laser scanning for transportation applications in Iowa. After an initial training period on the use of the scanner and Cyclone software, pilot tests were performed on the following projects: intersection and railroad bridge for training purposes; section of highway to determine elevation accuracy and pair of bridges to determine level of detail that can be captured; new concrete pavement to determine smoothness; bridge beams to determine camber for deck-loading calculations; stockpile to determine volume; and borrow pit to determine volume. Results show that it is possible to obtain 2-6 mm precision with the laser scanner as claimed by the manufacturer compared to approximately one-inch precision with aerial photogrammetry using a helicopter. A cost comparison between helicopter photogrammetry and laser scanning showed that laser scanning was approximately 30 percent higher in cost depending on assumptions. Laser scanning can become more competitive to helicopter photogrammetry by elevating the scanner on a boom truck and capturing both sides of a divided roadway at the same time. Two- and three-dimensional drawings were created in MicroStation for one of the scanned highway bridges. It was demonstrated that it is possible to create such drawings within the accuracy of this technology. It was discovered that a significant amount of time is necessary to convert point cloud images into drawings. As this technology matures, this task should become less time consuming. It appears that laser scanning technology does indeed have a place in the Iowa Department of Transportation design and construction toolbox. Based on results from this study, laser scanning can be used cost effectively for preliminary surveys to develop TIN meshes of roadway surfaces. It also appears that this technique can be used quite effectively to measure bridge beam camber in a safer and quicker fashion compared to conventional approaches. Volume calculations are also possible using laser scanning. It seems that measuring quantities of rock could be an area where this technology would be quite beneficial since accuracy is more important with this material compared to soil. Other applications for laser scanning could include developing as-built drawings of historical structures such as the bridges of Madison County. This technology could also be useful where safety is a concern such as accurately measuring the surface of a highway active with traffic or scanning the underside of a bridge damaged by a truck. It is recommended that the Iowa Department of Transportation initially rent the scanner when it is needed and purchase the software. With time, it may be cost justifiable to purchase the scanner as well. Laser scanning consultants can be hired as well but at a higher cost.

Iowa Department of Transportation Major Items - Preliminary Quantity Report, July 19, 2016; With Addendums

Weekly letting report

Factors influencing stability of granular base course mixes, 1969

The objectives of this final report; Iowa Highway Research Board Project HR-99 by J.M. Hoover, was to evaluate the various factors influencing the stability of granular base course mixes.

List of Bid Proposal Holders; Letting date: June 21, 2016

List of information of Bid Proposal Holders

2017-2021 Iowa Transportation Improvement Program

This document describes planned investments in Iowa’s multimodal transportation system including aviation, transit, railroads, trails, and highways. This five-year program documents $3.5 billion of highway and bridge construction projects on the primary road system using federal and state funding. Of that funding, a little over $500 million is available due to the passage of Senate File 257 in February 2015. As required by Senate File 257, this program includes a list of the critical highway and bridge projects funded with the additional revenue. Since last year’s program, a new federal surface transportation authorization bill was passed and signed into law. This authorization bill is titled Fixing America’s Surface Transportation (FAST) Act. The FAST Act, for the first time in many years, provides federal funding certainty over most of the time covered by this Program. In addition, it provided additional federal funding for highway and bridge projects.

Development of a Rational Characterization Method for Iowa Fly Ash, HR-286, Annual Progress Report 1, 1986

The following report summarizes research activities on the project for the period December 1, 1985 through November 31, 1986. Research efforts for the first year have proceeded basically as outlined in the project proposal.

Development of a Rational Characterization Method for Iowa Fly Ash, HR-286, Annual Progress Report 2, 1987

The following report summarizes research activities on the project for the period December 1, 1986 to November 30, 1987. Research efforts for the second year deviated slightly from those described in the project proposal. By the end of the second year of testing, it was possible to begin evaluating how power plant operating conditions influenced the chemical and physical properties of fly ash obtained from one of the monitored power plants (Ottumwa Generating Station, OGS). Hence, several of the tasks initially assigned to the third year of the project (specifically tasks D, E, and F) were initiated during the second year of the project. Manpower constraints were balanced by delaying full scale implementation of the quantitative X-ray diffraction and differential thermal analysis tasks until the beginning of the third year of the project. Such changes should have little bearing on the outcome of the overall project.