Clear Zone – A Synthesis of Practice and an Evaluation of the Benefi ts of Meeting the 10-ft Clear Zone Goal on Urban Streets, November 2008

In urban communities, there are often limited amounts of right-of-way available for establishing a large setback distance from the curb for fixed objects. Urban communities must constantly weigh the cost of purchasing additional right-of-way for clear zones against the risk of fixed object crashes. From 2004 to 2006, this type of crash on curbed roads represented 15% of all fatal crashes and 3% of all crashes in the state of Iowa. Many states have kept the current minimum AASHTO recommendations as their minimum clear zone standards; however, other states have decided that these recommendations are insufficient and have increased the required minimum clear zone distance to better suit the judgment of local designers. This report presents research on the effects of the clear zone on urban curbed streets. The research was conducted in two phases. The first phase involved a synthesis of practice that included a literature review and a survey of practices in jurisdictions that have developmental and historical patterns similar to those of Iowa. The second phase involved investigating the benefits of a 10 ft clear zone, which included examining urban corridors in Iowa that meet or do not meet the 10 ft clear zone goal. The results of this study indicate that a consistent fixed object offset results in a reduction in the number of fixed object crashes, a 5 ft clear zone is most effective when the goal is to minimize the number of fixed object c ashes, and a 3 ft clear zone is most effective when the goal is to minimize the cost of fixed object crashes.

Substitutable Concrete Pavements: A Manual of Practice, August 2011

Developed as a more detailed follow up at a 2009 briefing document,Building Sustainable Pavement with Concrete, this guide provides a clear, concise and cohesive discussion of pavement sustainability concepts and of recommended practices for maximizing the sustainability of concrete pavements. The intended audience includes decisions makers and practitioners in both owner-agencies and supply, manufacturing consulting and contractor businesses. Readers will find individual chapters with the most recent technical information and best practices related to concrete pavement deign, materials, construction, use/operations, renewal and recycling. In addition, they will find chapters addressing issues specific to pavement sustainability in the urban environment and to the evaluation of pavement sustainability.

Sustainable Concrete Pavements: A Manual of Practice, January 2012

Sustainable Concrete Pavements: A Manual of Practice is a product of the National Concrete Pavement Technology Center at Iowa State University’s Institute for Transportation, with funding from the Federal Highway Administration (DTFH61-06-H-00011, Work Plan 23). Developed as a more detailed follow-up to a 2009 briefing document, Building Sustainable Pavement with Concrete, this guide provides a clear, concise, and cohesive discussion of pavement sustainability concepts and of recommended practices for maximizing the sustainability of concrete pavements. The intended audience includes decision makers and practitioners in both owner-agencies and supply, manufacturing, consulting, and contractor businesses. Readers will find individual chapters with the most recent technical information and best practices related to concrete pavement design, materials, construction, use/operations, renewal, and recycling. In addition, they will find chapters addressing issues specific to pavement sustainability in the urban environment and to the evaluation of pavement sustainability. Development of this guide satisfies a critical need identified in the Sustainability Track (Track 12) of the Long-Term Plan for Concrete Pavement Research and Technology (CP Road Map). The CP Road Map is a national research plan jointly developed by the concrete pavement stakeholder community, including Federal Highway Administration, academic institutions, state departments of transportation, and concrete pavement–related industries. It outlines 12 tracks of priority research needs related to concrete pavements. CP Road Map publications and other operations support services are provided by the National Concrete Pavement Technology Center at Iowa State University. For details about the CP Road Map, see www.cproadmap. org/index.cfm.

Rural Expressway Intersection Synthesis of Practice and Crash Analysis, 2004

This report presents a national synthesis of rural expressway, two-way stop -controlled (TWSC) intersection safety strategies and intersection designs and an analysis of Iowa expressway TWSC intersection crash characteristics. A rural expressway is a multi-lane highway with a divided median and with mostly at -grade intersections, although some intersections may be grade separated. The synthesis of intersection strategies is conducted in two parts. The first is a literature review and the second part is a national survey of strategies currently being applied by state transportation agencies. The characterization of crash patterns at TWSC expressway intersections is examined through the analysis of 5 years of crash data at 644 intersections.

County condemnation manual : manual of practice and procedure for the acquisition of real property through the exercise of the power of eminent domain, 1995

This manual contains a summary of acquisition policy and makes recommendations to implement law and policy.

Survey of Dentists Iowa, 1973

This 1973 Survey of Dentists shows the number of dentists actively practicing in Iowa by county, age group, and type of practice.

1974 Survey of Dentists

This 1974 Survey of Dentists shows the number of dentists actively practicing in Iowa by county, age group, and type of practice.

Safety and Mobility Impacts of Winter Weather – Phase I, August 2011

Highway agencies spend millions of dollars to ensure safe and efficient winter travel. However, the effectiveness of winter weather maintenance practices on safety and mobility are somewhat difficult to quantify. Phase I of this project investigated opportunities for improving traffic safety on state-maintained roads in Iowa during winter weather conditions. The primary objective was to develop several preliminary means for the Iowa Department of Transportation (DOT) to identify locations of possible interest systematically with respect to winter weather-related safety performance based on crash history. Specifically, metrics were developed to assist in identifying possible habitual, winter weather-related crash sites on state-maintained rural highways in Iowa. In addition, the current state of practice, for both domestic and international highway agency practices, regarding integration of traffic safety- and mobility-related data in winter maintenance activities and performance measures were investigated. This investigation also included previous research efforts. Finally, a preliminary work plan, focusing on systematic use of safety-related data in support of winter maintenance activities and site evaluation, was prepared.

Development of a New Process for Determining Design Year Traffic Demands, TR-528, 2007

Researchers should continuously ask how to improve the models we rely on to make financial decisions in terms of the planning, design, construction, and maintenance of roadways. This project presents an alternative tool that will supplement local decision making but maintain a full appreciation of the complexity and sophistication of today’s regional model and local traffic impact study methodologies. This alternative method is tailored to the desires of local agencies, which requested a better, faster, and easier way to evaluate land uses and their impact on future traffic demands at the sub-area or project corridor levels. A particular emphasis was placed on scenario planning for currently undeveloped areas. The scenario planning tool was developed using actual land use and roadway information for the communities of Johnston and West Des Moines, Iowa. Both communities used the output from this process to make regular decisions regarding infrastructure investment, design, and land use planning. The City of Johnston case study included forecasting future traffic for the western portion of the city within a 2,600-acre area, which included 42 intersections. The City of West Des Moines case study included forecasting future traffic for the city’s western growth area covering over 30,000 acres and 331 intersections. Both studies included forecasting a.m. and p.m. peak-hour traffic volumes based upon a variety of different land use scenarios. The tool developed took goegraphic information system (GIS)-based parcel and roadway information, converted the data into a graphical spreadsheet tool, allowed the user to conduct trip generation, distribution, and assignment, and then to automatically convert the data into a Synchro roadway network which allows for capacity analysis and visualization. The operational delay outputs were converted back into a GIS thematic format for contrast and further scenario planning. This project has laid the groundwork for improving both planning and civil transportation decision making at the sub-regional, super-project level.

Development of a Transportation and Land Use Public Policy Education Program for Iowa, 2000

This literature review serves as a foundation for a transportation and land use public policy education program for Iowa. The objective of the review is to summarize relevant research findings, to review the state of practice and policies of other state and local governments, and to explore land use trends both within the state of Iowa and the nation as a whole. Much of what we learned has been incorporated into the course materials. Because we expect to identify more useful sources throughout the project, this literature review should be considered a work in progress.