Road Safety Audit for IA 28 from the South Corporate Limits of Norwalk in Warren County through the IA 5 Interchange in Polk County, Iowa, November 2012

In response to local concerns, the Iowa Department of Transportation (DOT) requested a road safety audit (RSA) for the IA Highway 28 corridor through the City of Norwalk in Warren County, Iowa, from the south corporate limits of Norwalk through the IA 5 interchange in Polk County, Iowa. The audit included meeting with City staff to discuss concerns, review crash history and operational issues, observe the route under daylight and nighttime conditions, and analyze available data. This report outlines the findings and recommendations of the audit team for addressing the safety concerns and operational matters along this corridor.

Modified Sheet Pile Abutments for Low-Volume Road Bridges, January 2012

To date there have been few investigations of the substructures in low-volume road (LVR) bridges. Steel sheet piling has the potential to provide an economical alternative to concrete bridge abutments, but it needs investigation with regard to vertical and lateral load resistance, construction methods, and performance monitoring. The objectives of this project were to develop a design approach for sheet pile bridge abutments for short-span low-volume bridges, formulate an instrumentation and monitoring plan to evaluate performance of sheet pile abutment systems, and understand the cost and construction effort associated with building the sheet pile bridge abutment demonstration project. Three demonstration projects (Boone, Blackhawk, and Tama Counties) were selected for the design, construction, and monitoring of sheet pile abutments bridges. Each site was unique and required site-specific design and instrumentation monitoring. The key findings from this study include the following: (1) sheet pile abutment bridges provide an effective solution for LVR bridges, (2) the measured stresses and deflection were different from the assumed where the differences reflect conservatism in the design and the complex field conditions, and (3) additional research is needed to optimize the design.

Modified Sheet Pile Abutments for Low-Volume Road Bridges: Tech Transfer Summary, January 2012

Iowa has about 22,936 bridges on low-volume roads (LVRs). Based on the National Bridge Inventory data, 22 percent of the LVR bridges in Iowa are structurally deficient, while 5 percent of them are functionally obsolete. The substructure components (abutment and foundation elements) are known to be contributing factors for some of these poor ratings. Steel sheet piling was identified as a possible long-term option for LVR bridge substructures; but, due to lack of experience, Iowa needed investigation with regard to vertical and lateral load resistance, construction methods, design methodology, and load test performance. This project was initiated in January 2007 to investigate use of sheet pile abutments. *************Tech Transfer Summary. For full report see: http://publications.iowa.gov/id/eprint/14832*************

Improved myocardial tagging contrast in cine balanced SSFP images.

PURPOSE: To improve the tag persistence throughout the whole cardiac cycle by providing a constant tag-contrast throughout all the cardiac phases when using balanced steady-state free precession (bSSFP) imaging. MATERIALS AND METHODS: The flip angles of the imaging radiofrequency pulses were optimized to compensate for the tagging contrast-to-noise ratio (Tag-CNR) fading at later cardiac phases in bSSFP imaging. Complementary spatial modulation of magnetization (CSPAMM) tagging was implemented to improve the Tag-CNR. Numerical simulations were performed to examine the behavior of the Tag-CNR with the proposed method, and to compare the resulting Tag-CNR with that obtained from the more commonly used spoiled gradient echo (SPGR) imaging. A gel phantom, as well as five healthy human volunteers, were scanned on a 1.5T scanner using bSSFP imaging with and without the proposed technique. The phantom was also scanned with SPGR imaging. RESULTS: With the proposed technique, the Tag-CNR remained almost constant during the whole cardiac cycle. Using bSSFP imaging, the Tag-CNR was about double that of SPGR. CONCLUSION: The tag persistence was significantly improved when the proposed method was applied, with better Tag-CNR during the diastolic cardiac phase. The improved Tag-CNR will support automated tagging analysis and quantification methods.

Road Use Tax Fund Efficiency Report, September 2013

Senate File 2314, 84th General Assembly, states the Iowa Department of Transportation shall submit quarterly reports regarding the implementation of efficiency measures identified in the "Road Use Tax Fund Efficiency Report," January 2012. This report shall provide details of activities undertaken in the previous quarter relating to one-time and long-term program efficiencies and partnership efficiencies. Issues covered include savings realized from the implementation of particular efficiency measures; updates concerning measures that have not been implemented; efforts involving cities, counties, other jurisdictions, or stakeholder interest groups; any new efficiency measures identified or undertaken; and identification of any legislative action that may be required to achieve efficiencies.

Rockfall induced seismic signals: case study in Montserrat, Catalonia

After a rockfall event, a usual post event survey includes qualitative volume estimation, trajectory mapping and determination of departing zones. However, quantitative measurements are not usually made. Additional relevant quantitative information could be useful in determining the spatial occurrence of rockfall events and help us in quantifying their size. Seismic measurements could be suitable for detection purposes since they are non invasive methods and are relatively inexpensive. Moreover, seismic techniques could provide important information on rockfall size and location of impacts. On 14 February 2007 the Avalanche Group of the University of Barcelona obtained the seismic data generated by an artificially triggered rockfall event at the Montserrat massif (near Barcelona, Spain) carried out in order to purge a slope. Two 3 component seismic stations were deployed in the area about 200 m from the explosion point that triggered the rockfall. Seismic signals and video images were simultaneously obtained. The initial volume of the rockfall was estimated to be 75 m3 by laser scanner data analysis. After the explosion, dozens of boulders ranging from 10¿4 to 5 m3 in volume impacted on the ground at different locations. The blocks fell down onto a terrace, 120 m below the release zone. The impact generated a small continuous mass movement composed of a mixture of rocks, sand and dust that ran down the slope and impacted on the road 60 m below. Time, time-frequency evolution and particle motion analysis of the seismic records and seismic energy estimation were performed. The results are as follows: 1 ¿ A rockfall event generates seismic signals with specific characteristics in the time domain; 2 ¿ the seismic signals generated by the mass movement show a time-frequency evolution different from that of other seismogenic sources (e.g. earthquakes, explosions or a single rock impact). This feature could be used for detection purposes; 3 ¿ particle motion plot analysis shows that the procedure to locate the rock impact using two stations is feasible; 4 ¿ The feasibility and validity of seismic methods for the detection of rockfall events, their localization and size determination are comfirmed.

Road Use Tax Fund Efficiency Report, December 31, 2013

Senate File 2314, 84th General Assembly, states the Iowa Department of Transportation shall submit quarterly reports regarding the implementation of efficiency measures identified in the "Road Use Tax Fund Efficiency Report," January 2012. This report shall provide details of activities undertaken in the previous quarter relating to one-time and long-term program efficiencies and partnership efficiencies. Issues covered include savings realized from the implementation of particular efficiency measures; updates concerning measures that have not been implemented; efforts involving cities, counties, other jurisdictions, or stakeholder interest groups; any new efficiency measures identified or undertaken; and identification of any legislative action that may be required to achieve efficiencies.

The Wever Bypass excavations: Highway archaeology along the Great River Road in southeast Iowa.

This is a story about a highway project near the small town of Wever, Iowa, and an American Indian village that existed at the location prior to the Europeans' arrival. The culture that lived in this village existed in a 10 state region of the Upper Midwest and may have been the ancestors of tribes living in the Midwest when European explorers entered the region. An archaeological recovery of information from the site was undertaken by the Iowa Department of Transportation because four-lane construction of U.S. 61 could not be accomplished without destroying most of the site. This site proved to be one of the richest archaeological finds in the State of Iowa. ǂc Iowa Department of Transportation.

The Economics of Reducing the County Road System: Three Case Studies in Iowa - Executive Summary, HR-242, 1986

This Executive Summary presents a brief summary of the main research report, "The Economics of Reducing the County Road System: Three Case Studies in Iowa" (DOT/OST/P-34/86-035). The case studies are described, as well as the analytic methodology and research findings.

The Economics of Reducing the County Road System: Three Case Studies in Iowa, HR-242, 1986

This research project looked at the economic benefits and costs associated with alternative strategies for abandoning low volume rural highways and bridges. Three test counties in Iowa were studied, each 100 square miles in size: Hamilton County having a high agricultural tax base and a high percentage of paved roads and few bridges; Shelby County having a relatively low agricultural tax base, hilly terrain and a low percentage of paved road and many bridges; and Linn County having a high agricultural tax base, a high percentage of paved roads and a large number of non-farm households. A questionnaire survey was undertaken to develop estimates of farm and household travel patterns. Benefits and costs associated with the abandonment of various segments of rural highway and bridge mileages in each county were calculated. "Benefits" calculated were reduced future reconstruction and maintenance costs, whereas "costs" were the added cost of travel resulting from the reduced mileage. Some of the findings suggest limited cost savings from abandonment of county roads with no property access in areas with large non-farm rural population; relatively high cost savings from the abandonment of roads with no property access in areas with small rural population; and the largest savings from the conversion of public dead-end gravel roads with property or residence accesses to private drives.

An Investigation of Signing Needs at Uncontrolled Local Road Intersections, HR-230, 1982

Iowa Counties have been experiencing significant tort claim liability due to the signing of local roads. One such problem is relative to the real or alleged need for signing at uncontrolled intersections of local roads. It has been assumed that the standard CROSS ROAD sign, which calls for a yellow diamond with a black cross, was sufficient to provide the necessary warning that a driver may be approaching an intersection which requires special precautionary driving attention. However, it is possible that this sign on a through highway might conflict with the legal status of the local county road. In light of this situation, it seemed worthwhile to know the extent to which uncontrolled local road intersections were perceived as a potential liability problem; the degree to which the standard CROSS ROAD sign communicated to the driver the message a county engineer wanted at these local road intersections; and whether there were any better signing alternatives available to communicate this hazard to the driver in this situation.

Distributing State Road Use Tax Funds to Counties, HR-386, 1996

Iowa's county road system serves many critical functions in a changing environment. Many counties with very different social, economic, and demographic circumstances do not have adequate resources to provide the desired level of service on their secondary road systems. How the state's Road Use Tax Fund (RUTF) is distributed among counties is therefore of great importance. This report presents the results of a year-long study of how to distribute RUTF resources among Iowa's 99 counties. The project was undertaken at the request of county engineers who wish to replace the current method of allocation with one that is more stable, comprehensible, and predictable. This report describes the current allocation method, examines how other states distribute road funds to counties, and discusses potential allocation factors that could be included in a revised procedure. The process undertaken to narrow the range of possible formulas and determine the one to recommend is summarized. Finally, the report presents the allocation formula recommended by the project advisory committee, along with how it would operate.