Synthesis of Nondestructive Testing Technologies for Geomaterial Applications, May 2005

Current monitoring techniques for determination of compaction of earthwork and asphalt generally involve destructive testing of the materials following placement. Advances in sensor technologies show significant promise for obtaining necessary information through nondestructive and remote techniques. To develop a better understanding of suitable and potential technologies, this study was undertaken to conduct a synthesis review of nondestructive testing technologies and perform preliminary evaluations of selected technologies to better understand their application to testing of geomaterials (soil fill, aggregate base, asphalt, etc.). This research resulted in a synthesis of potential technologies for compaction monitoring with a strong emphasis on moisture sensing. Techniques were reviewed and selectively evaluated for their potential to improve field quality control operations. Activities included an extensive review of commercially available moisture sensors, literature review, and evaluation of selected technologies. The technologies investigated in this study were dielectric, nuclear, near infrared spectroscopy, seismic, electromagnetic induction, and thermal. The primary disadvantage of all the methods is the small sample volume measured. In addition, all the methods possessed some sensitivity to non-moisture factors that affected the accuracy of the results. As the measurement volume increases, local variances are averaged out providing better accuracy. Most dielectric methods with the exception of ground penetrating radar have a very small measurement volume and are highly sensitive to variations in density, porosity, etc.

Remote Sensing (LIDAR) for Management of Highway Assets for Safety, 2003

The main objective of this study was to utilize light detection and ranging (LIDAR) technology to obtain highway safety-related information. The safety needs of older drivers in terms of prolonged reaction times were taken into consideration. The tasks undertaken in this study were (1) identification of crashes that older drivers are more likely to be involved in, (2) identification of highway geometric features that are important in such crashes, (3) utilization of LIDAR data for obtaining information on the identified highway geometric features, and (4) assessment of the feasibility of using LIDAR data for such applications. A review of previous research indicated that older drivers have difficulty negotiating intersections, and it was recognized that intersection sight triangles were critical to safe intersection negotiation. LIDAR data were utilized to obtain information on potential sight distance obstructions at six selected intersections located on the Iowa Highway 1 corridor by conducting in-office line-of-sight analysis. Crash frequency, older driver involvement, and data availability were considerations in the selection of the six intersections. Results of the in-office analysis were then validated by visiting the intersections in the field. Sixty-six potential sight distance obstructions were identified by the line-of-sight analysis, out of which 62 (89.8%) were confirmed while four (5.8%) were not confirmed by the video. At least three (4.4%) potential sight distance obstructions were discovered in the video that were not detected by the line-of-sight analysis. The intersection with the highest crash frequency involving older drivers was correctly found to have obstructions located within the intersection sight triangles. Based on research results, it is concluded that LIDAR data can be utilized for identifying potential sight distance obstructions at intersections. The safety of older drivers can be enhanced by locating and rectifying intersections with obstructions in sight triangles.

A-7 Statistical Report On FIP Applications And Cases Discontinued, December 2003

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, January 2004

Monthly statistical report on FIP by the Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, February 2004

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, March 2004

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, May 2004

Monthly statistical report on FIP by the Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, July 2002

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, September 2003

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, November 2001

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, January 2002

Monthly statistical report on FIP by Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, June 2004

Monthly statistical report on FIP by the Iowa Department of Human Services

A-7 Statistical Report On FIP Applications And Cases Discontinued, July 2004

Statistical Report On FIP Applications And Cases Discontinued

A-7 Statistical Report On FIP Applications And Cases Discontinued, August 2004

Statistical Report On FIP Applications And Cases Discontinued

A-7, Statistical Report On FIP Applications And Cases Discontinued, September 2004

Statistical Report On FIP Applications And Cases Discontinued