Learn about the Land - A Geologic Guide to the RAGBRAI Challenge, July 2006

Thie bourchure that is produced by the Iowa Geological Society, talks about points of interest to people that are biking accross Iowa. Part of RAGBRAI.

Bedrock Geologic Map of Iowa, 1998

Geologic map of Iowa in 1998

Learn about the Land - A Geologic Guide to the RAGBRAI Challenge, July 2007

Thie bourchure that is produced by the Iowa Geological Society, talks about points of interest to people that are biking accross Iowa. Part of RAGBRAI.

Population by Age Group and % of Total Population, 2007

Estimates/projections for age 60+ for the state and for its counties and incorporated places. DEA also provides population estimates on poverty, race and ethnicity, and urban and rural for age 60+. This statistical information is obtained from numerous resources, including the State Data Center of Iowa, US Census Bureau, the Administration on Aging, and Iowa State University Census Services. "The Census Bureau uses the latest available estimates as starting points for population projections. Sometimes the user may see both an estimate and a projection available for the same reference date, which may not agree because they were produced at different times. In such cases, estimates are the preferred data." (Source: State Data Center)

Population by Age Group and Perecnt of Total Popluation by County, 2006

The Department of Elder Affairs maintains and provides population and demographic estimates/projections for age 60+ for the state and for its counties and incorporated places. DEA also provides population estimates on poverty, race and ethnicity, and urban and rural for age 60+. This statistical information is obtained from numerous resources, including the State Data Center of Iowa, US Census Bureau, the Administration on Aging, and Iowa State University Census Services. "The Census Bureau uses the latest available estimates as starting points for population projections. Sometimes the user may see both an estimate and a projection available for the same reference date, which may not agree because they were produced at different times. In such cases, estimates are the preferred data." (Source: State Data Center)

Information on Iowa’s Graduated Driver Licensing system for drivers under the age of 18, February 3, 2012

Information in this Q and A brochure was provided and produced by the Iowa Department of Transportation.

Decision Support Model for Assessing Archaeological Survey Needs for Bridge Replacement Projects in Iowa, 2006

The Bridges Decision Support Model is a geographic information system (GIS) that assembles existing data on archaeological sites, surveys, and their geologic contexts to assess the risk of bridge replacement projects encountering 13,000- to 150-year-old Native American sites. This project identifies critical variables for assessing prehistoric sites potential, examines the quality of available data about the variables, and applies the data to creating a decision support framework for use by the Iowa Department of Transportation (Iowa DOT) and others. An analysis of previous archaeological surveys indicates that subsurface testing to discover buried sites became increasingly common after 1980, but did not become routine until after the adoption of guidelines recommending such testing, in 1993. Even then, the average depth of testing has been relatively shallow. Alluvial deposits of sufficient age, deposited in depositional environments conducive to human habitation, are considerably thicker than archaeologists have routinely tested.

Age vs. Experience: Evaluation of a Video Feedback Intervention for Newly Licensed Teen Drivers, TPF-5(207), 2013

This project examines the effects of age, experience, and video-based feedback on the rate and type of safety-relevant events captured on video event recorders in the vehicles of three groups of newly licensed young drivers: 1. 14.5- to 15.5-year-old drivers who hold a minor school license (see Appendix A for the provisions of the Iowa code governing minor school licenses); 2. 16-year-old drivers with an intermediate license who are driving unsupervised for the first time; 3. 16-year-old drivers with an intermediate license who previously drove unsupervised for at least four months with a school license. METHODS: The young drivers’ vehicles were equipped with an event-triggered video recording device for 24 weeks. Half of the participants received feedback regarding their driving, and the other half received no feedback at all and served as a control group. The number of safety-relevant events per 1,000 miles (i.e., “event rate”) was analyzed for 90 participants who completed the study. RESULTS: On average, the young drivers who received the video-based intervention had significantly lower event rates than those in the control group. This finding was true for all three groups. An effect of experience was seen for drivers in the control group; the 16-year-olds with driving experience had significantly lower event rates than the 16-year-olds without experience. When the intervention concluded, an increase in event rate was seen for the school license holders, but not for either group of 16-year-old drivers. There is strong evidence that giving young drivers video-based feedback, regardless of their age or level of driving experience, is effective in reducing the rate of safety-relevant events relative to a control group who do not receive feedback. Specific comparisons with regard to age and experience indicated that the age of the driver did not have an effect on the rate of safety-events, while experience did. Young drivers with six months or more of additional experience behind the wheel had nearly half as many safety-relevant events as those without that experience.

Iowa Ultra Thin Whitetopping at Two Years of Age, HR-559, 1996

An 11.6 km research project was constructed in 1994 on a portion of Iowa Highway 21 in Iowa County, from U.S. 6 to Iowa Highway 212. This research is intended to evaluate the effect of four primary variables on long term performances of the PCC concrete overlay, commonly called whitetopping. The variables are thickness (50 mm, 100 mm, 150 mm, and 200 mm), joint spacing (0.6 m squares, 1.2 m squares, 1.8 m squares, and 4.6 m spacing), fiber use (concrete with and without polypropolene fibers) and surface preparation (patch only, scarifying the surface, and cold-in-place recycling). After two years, only two sections exhibit a small amount of debonding and distress cracking. Both sections are 50 mm thick. Within each of these two sections, only 2% of the area is affected. Two other 50 mm thick sections have a small number of cracks but no debonding has been found. No adverse effects of these cracks are evident. Three asphalt overlay sections were also constructed. In each asphalt section, transverse cracks have recently been found. At two years of age, the research sections are performing very well. An insignificant number of cracks and no distressed areas have been found in any research sections thicker than 50 mm.

Geologic and Engineering Properties of Pleistocene Materials in Iowa, Iowa Highway Research Board Bulletin No. 20, 1960

This bulletin is a compilation of the reports on completed research done for the Iowa State Highway Research Board Project HR-1, "The Loess and Glacial Till Materials of Iowa; an Investigation of Their Physical and Chemical Properties and Techniques for Processing Them to Increase Their All-Weather Stability for Road Construction.” The research, started in 1950, was done by the Iowa Engineering Experiment Station under its project 283-S. The project was supported by funds from the Iowa State Highway Commission.