Iowa Uniform Crime Report, 2004

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Iowa Uniform Crime Report, 2005

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Iowa Uniform Crime Report, 2006

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Iowa Uniform Crime Report, 2007

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Iowa Uniform Crime Report, 2008

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Iowa Uniform Crime Report, 2009

The National Uniform Crime Reporting System began with 400 cities representing 20 million inhabitants in 43 states on January 1st, 1930. Since the establishment of the Uniform Crime Reporting Program, the volume, diversity, and complexity of crime steadily increased while the UCR program remained virtually unchanged. Recognizing the increasing need for more in-depth statistical information and the need to improve the methodology used for compiling, analyzing, auditing, and publishing the collected data, an extensive study of the Uniform Crime reports was undertaken. The objective of this study was to meet law enforcement needs into the 21st century. The result of the study was NIBRS (National Incident Based Reporting System). Adoption of the NIBRS system took place in the mid 1980’s and Iowa began organizational efforts to implement the system. Conversion to IBR (Incident Based Iowa Uniform Crime Reporting) was completed January 1, 1991, as part of a national effort to implement incident based crime reporting, coordinated by the Federal Bureau of Investigation and the Bureau of Justice Statistics of the U.S. Department of Justice. Iowa was the fifth state in the nation to be accepted as a certified “reporting state” of incident based crime data to the national system.

Metric Short Course for the Office of Bridges and Structures, HR-378, 1995

This metric short course was developed in response to a request from the Office of Bridges and Structures to assist in the training of engineers in the use of metric units of measure which will be required in all highway designs and construction after September 30, 1996 (CFR Presidential Executive Order No. 12770). The course notes which are contained in this report, were developed for a half-day course. The course contains a brief review of metrication in the U.S., metric units, prefixes, symbols, basic conversions, etc. The unique part of the course is that it presents several typical bridge calculations (such as capacity of reinforced concrete compression members, strength of pile caps, etc.) worked two ways: inch-pound units throughout with end conversion to metric and initial hard conversion to metric with metric units throughout. Comparisons of partial results and final results (obtained by working the problems the two ways) are made for each of the example problems.

Demonstration Project 85, Video Imagery Systems for Highway Applications, HR-1047, 1990

The report describes the state of the art video equipment used and experiences gained from the 6,800 mile field test. The first objective of this project was to determine if laser disc equipment could capture and store usable roadway images while operating in a mobile environment. The second objective was to evaluate methods of using optical disc storage and retrieval features to enhance highway planning and design function. Several highway departments have attempted to use video technology to replace the traditional 16 and 35 mm film format used in photologging. These attempts have met with limited success because of the distortion caused by video technology not being capable of dealing with highway speeds. The distortion has caused many highway signs to be unreadable and, therefore, clients have labeled the technology unusable. Two methods of using optical laser disc storage and retrieval have been successfully demonstrated by Wisconsin and Connecticut Departments of Transportation. Each method provides instantaneous retrieval and linking of images with other information. However, both methods gather the images using 35 mm film techniques. The 35 mm film image is then transferred to laser disc. Eliminating the film conversion to laser disc has potential for saving $4 to $5 per logging mile. In addition to a cost savings, the image would be available immediately as opposed to delays caused by film developing and transferring to laser disc. In June and November of 1986 Iowa DOT staff and cooperating equipment suppliers demonstrated the concept of direct image capture. The results from these tests were promising and an FHWA Demonstration program established. Since 1986 technology advancements have been incorporated into the design that further improve the image quality originally demonstrated.

Guidelines for the Conversion of Urban Four-Lane Undivided Roadways to Three-Lane Two-Way Left-turn Lane Facilities, April 2001

Four-lane undivided roadways in urban areas can experience a degradation of service and/or safety as traffic volumes increase. In fact, the existence of turning vehicles on this type of roadway has a dramatic effect on both of these factors. The solution identified for these problems is typically the addition of a raised median or two-way left-turn lane (TWLTL). The mobility and safety benefits of these actions have been proven and are discussed in the “Past Research” chapter of this report along with some general cross section selection guidelines. The cost and right-of-way impacts of these actions are widely accepted. These guidelines focus on the evaluation and analysis of an alternative to the typical four-lane undivided cross section improvement approach described above. It has been found that the conversion of a four-lane undivided cross section to three lanes (i.e., one lane in each direction and a TWLTL) can improve safety and maintain an acceptable level of service. These guidelines summarize the results of past research in this area (which is almost nonexistent) and qualitative/quantitative before-and-after safety and operational impacts of case study conversions located throughout the United States and Iowa. Past research confirms that this type of conversion is acceptable or feasible in some situations but for the most part fails to specifically identify those situations. In general, the reviewed case study conversions resulted in a reduction of average or 85th percentile speeds (typically less than five miles per hour) and a relatively dramatic reduction in excessive speeding (a 60 to 70 percent reduction in the number of vehicles traveling five miles per hour faster than the posted speed limit was measured in two cases) and total crashes (reductions between 17 to 62 percent were measured). The 13 roadway conversions considered had average daily traffic volumes of 8,400 to 14,000 vehicles per day (vpd) in Iowa and 9,200 to 24,000 vehicles per day elsewhere. In addition to past research and case study results, a simulation sensitivity analysis was completed to investigate and/or confirm the operational impacts of a four-lane undivided to three-lane conversion. First, the advantages and disadvantages of different corridor simulation packages were identified for this type of analysis. Then, the CORridor SIMulation (CORSIM) software was used x to investigate and evaluate several characteristics related to the operational feasibility of a four-lane undivided to three-lane conversion. Simulated speed and level of service results for both cross sections were documented for different total peak-hour traffic, access densities, and access-point left-turn volumes (for a case study corridor defined by the researchers). These analyses assisted with the identification of the considerations for the operational feasibility determination of a four -lane to three-lane conversion. The results of the simulation analyses primarily confirmed the case study impacts. The CORSIM results indicated only a slight decrease in average arterial speed for through vehicles can be expected for a large range of peak-hour volumes, access densities, and access-point left-turn volumes (given the assumptions and design of the corridor case study evaluated). Typically, the reduction in the simulated average arterial speed (which includes both segment and signal delay) was between zero and four miles per hour when a roadway was converted from a four-lane undivided to a three-lane cross section. The simulated arterial level of service for a converted roadway, however, showed a decrease when the bi-directional peak-hour volume was about 1,750 vehicles per hour (or 17,500 vehicles per day if 10 percent of the daily volume is assumed to occur in the peak hour). Past research by others, however, indicates that 12,000 vehicles per day may be the operational capacity (i.e., level of service E) of a three-lane roadway due to vehicle platooning. The simulation results, along with past research and case study results, appear to support following volume-related feasibility suggestions for four-lane undivided to three-lane cross section conversions. It is recommended that a four-lane undivided to three-lane conversion be considered as a feasible (with respect to volume only) option when bi-directional peak-hour volumes are less than 1,500 vehicles per hour, but that some caution begin to be exercised when the roadway has a bi-directional peak-hour volume between 1,500 and 1,750 vehicles per hour. At and above 1,750 vehicles per hour, the simulation indicated a reduction in arterial level of service. Therefore, at least in Iowa, the feasibility of a four-lane undivided to three-lane conversion should be questioned and/or considered much more closely when a roadway has (or is expected to have) a peak-hour volume of more than 1,750 vehicles. Assuming that 10 percent of the daily traffic occurs during the peak-hour, these volume recommendations would correspond to 15,000 and 17,500 vehicles per day, respectively. These suggestions, however, are based on the results from one idealized case xi study corridor analysis. Individual operational analysis and/or simulations should be completed in detail once a four-lane undivided to three-lane cross section conversion is considered feasible (based on the general suggestions above) for a particular corridor. All of the simulations completed as part of this project also incorporated the optimization of signal timing to minimize vehicle delay along the corridor. A number of determination feasibility factors were identified from a review of the past research, before-and-after case study results, and the simulation sensitivity analysis. The existing and expected (i.e., design period) statuses of these factors are described and should be considered. The characteristics of these factors should be compared to each other, the impacts of other potentially feasible cross section improvements, and the goals/objectives of the community. The factors discussed in these guidelines include • roadway function and environment • overall traffic volume and level of service • turning volumes and patterns • frequent-stop and slow-moving vehicles • weaving, speed, and queues • crash type and patterns • pedestrian and bike activity • right-of-way availability, cost, and acquisition impacts • general characteristics, including - parallel roadways - offset minor street intersections - parallel parking - corner radii - at-grade railroad crossings xii The characteristics of these factors are documented in these guidelines, and their relationship to four-lane undivided to three-lane cross section conversion feasibility identified. This information is summarized along with some evaluative questions in this executive summary and Appendix C. In summary, the results of past research, numerous case studies, and the simulation analyses done as part of this project support the conclusion that in certain circumstances a four-lane undivided to three-lane conversion can be a feasible alternative for the mitigation of operational and/or safety concerns. This feasibility, however, must be determined by an evaluation of the factors identified in these guidelines (along with any others that may be relevant for a individual corridor). The expected benefits, costs, and overall impacts of a four-lane undivided to three-lane conversion should then be compared to the impacts of other feasible alternatives (e.g., adding a raised median) at a particular location.

The Effect of Four-Lane to Three-Lane Conversion on the Number of Crashes and Crash Rates in Iowa Roads, June 2005

We analyze crash data collected by the Iowa Department of Transportation using Bayesian methods. The data set includes monthly crash numbers, estimated monthly traffic volumes, site length and other information collected at 30 paired sites in Iowa over more than 20 years during which an intervention experiment was set up. The intervention consisted in transforming 15 undivided road segments from four-lane to three lanes, while an additional 15 segments, thought to be comparable in terms of traffic safety-related characteristics were not converted. The main objective of this work is to find out whether the intervention reduces the number of crashes and the crash rates at the treated sites. We fitted a hierarchical Poisson regression model with a change-point to the number of monthly crashes per mile at each of the sites. Explanatory variables in the model included estimated monthly traffic volume, time, an indicator for intervention reflecting whether the site was a “treatment” or a “control” site, and various interactions. We accounted for seasonal effects in the number of crashes at a site by including smooth trigonometric functions with three different periods to reflect the four seasons of the year. A change-point at the month and year in which the intervention was completed for treated sites was also included. The number of crashes at a site can be thought to follow a Poisson distribution. To estimate the association between crashes and the explanatory variables, we used a log link function and added a random effect to account for overdispersion and for autocorrelation among observations obtained at the same site. We used proper but non-informative priors for all parameters in the model, and carried out all calculations using Markov chain Monte Carlo methods implemented in WinBUGS. We evaluated the effect of the four to three-lane conversion by comparing the expected number of crashes per year per mile during the years preceding the conversion and following the conversion for treatment and control sites. We estimated this difference using the observed traffic volumes at each site and also on a per 100,000,000 vehicles. We also conducted a prospective analysis to forecast the expected number of crashes per mile at each site in the study one year, three years and five years following the four to three-lane conversion. Posterior predictive distributions of the number of crashes, the crash rate and the percent reduction in crashes per mile were obtained for each site for the months of January and June one, three and five years after completion of the intervention. The model appears to fit the data well. We found that in most sites, the intervention was effective and reduced the number of crashes. Overall, and for the observed traffic volumes, the reduction in the expected number of crashes per year and mile at converted sites was 32.3% (31.4% to 33.5% with 95% probability) while at the control sites, the reduction was estimated to be 7.1% (5.7% to 8.2% with 95% probability). When the reduction in the expected number of crashes per year, mile and 100,000,000 AADT was computed, the estimates were 44.3% (43.9% to 44.6%) and 25.5% (24.6% to 26.0%) for converted and control sites, respectively. In both cases, the difference in the percent reduction in the expected number of crashes during the years following the conversion was significantly larger at converted sites than at control sites, even though the number of crashes appears to decline over time at all sites. Results indicate that the reduction in the expected number of sites per mile has a steeper negative slope at converted than at control sites. Consistent with this, the forecasted reduction in the number of crashes per year and mile during the years after completion of the conversion at converted sites is more pronounced than at control sites. Seasonal effects on the number of crashes have been well-documented. In this dataset, we found that, as expected, the expected number of monthly crashes per mile tends to be higher during winter months than during the rest of the year. Perhaps more interestingly, we found that there is an interaction between the four to three-lane conversion and season; the reduction in the number of crashes appears to be more pronounced during months, when the weather is nice than during other times of the year, even though a reduction was estimated for the entire year. Thus, it appears that the four to three-lane conversion, while effective year-round, is particularly effective in reducing the expected number of crashes in nice weather.

The Conversion of Four Lane Undivded Urban Roadways to Three Lane Facilities, 2007

In recent years, many traffic engineers have advocated converting four-lane undivided urban streets to threelane two-way left-turn facilities. A number of these conversions have been successfully implemented. Accident rates have decreased while corridor and intersection levels of service remained acceptable. This conversion concept is yet another viable alternative “tool” to place in our urban safety/congestion toolbox.

Native Grassland Conversion: the Roles of Risk Intervention and Switching Costs

We develop a real option model of the irreversible native grassland conversion decision. Upon plowing, native grassland can be followed by either a permanent cropping system or a system in which land is put under cropping (respectively, grazing) whenever crop prices are high (respectively, low). Switching costs are incurred upon alternating between cropping and grazing. The effects of risk intervention in the form of crop insurance subsidies are studied, as are the effects of cropping innovations that reduce switching costs. We calibrate the model by using cropping return data for South Central North Dakota from 1989 to 2012. Simulations show that a risk intervention that offsets 20% of a cropping return shortfall increases the sod-busting cost threshold, below which native sod will be busted, by 41% (or $43.7/acre). Omitting cropping return risk across time underestimates this sod-busting cost threshold by 23% (or $24.35/acre), and hence underestimates the native sod conversion caused by crop production.

Visualization Resources for Iowa State University and the Iowa DOT: An Automated Design Model to Simulator Converter, November 2012

This project developed an automatic conversion software tool that takes input a from an Iowa Department of Transportation (DOT) MicroStation three-dimensional (3D) design file and converts it into a form that can be used by the University of Iowa’s National Advanced Driving Simulator (NADS) MiniSim. Once imported into the simulator, the new roadway has the identical geometric design features as in the Iowa DOT design file. The base roadway appears as a wireframe in the simulator software. Through additional software tools, textures and shading can be applied to the roadway surface and surrounding terrain to produce the visual appearance of an actual road. This tool enables Iowa DOT engineers to work with the universities to create drivable versions of prospective roadway designs. By driving the designs in the simulator, problems can be identified early in the design process. The simulated drives can also be used for public outreach and human factors driving research.