Many rural communities have developed around highways or major county roads. As a result, the main street through small rural communities is often part of a high-speed rural highway. Highways and county roads are characterized by high speeds outside the city limits and then transition into a reduced-speed section through the rural community. Consequently, drivers passing through the community may enter at high speeds and then maintain those speeds throughout. Traffic calming in small rural communities along major roadways is common in Europe, but the United States does not have experience with applying traffic calming outside of major urban areas. Seven different low-cost traffic treatments were implemented and evaluated in five rural Iowa communities. Two of the treatments physically affected the roadway cross-section. A speed table was placed along the major road (County Highway E-23) in Gilbert, Iowa, and longitudinal channelizers were used to create a center island narrowing along County Highway R-38 in Slater, Iowa. Before and after speed studies were conducted. Speed studies were conducted at 1, 3, 9, and 12 months after installation of the treatments to evaluate their effectiveness over time. Both treatments successfully reduced mean speed, 85th percentile speed, and fraction of vehicles traveling 5, 10, 15, and 20 mph over the posted speed limit; reductions were sustained over time.
A major problem in transportation modeling is the acquisition of quality employment data. Employment data are used in transportation planning to model the journey to work and other types of trips, but they rarely are collected solely for transportation purposes because of the large expense involved. Census data, on the other hand, are inexpensive but are collected only every 10 years (although the American Community Survey provides some continuous data). This presentation outlines and assesses a process to develop systems and protocols for using an already-collected set of detailed employment data for an alternative purpose, transportation planning. Tapping this source may provide an ongoing, economical, and annual source of important transportation data that allows planners to better model and predict transportation needs, from the commuter and the business perspective. A better understanding of travel patterns, in turn, helps planners to evaluate investments in fixed physical infrastructure and public transportation. The data set also has valuable uses in other fields, such as workforce development planning, economic development, land use planning, and social service delivery. The success of this project required intergovernmental cooperation from several key partners.
According to the Iowa Department of Transportation's crash database (GIS-ALAS), between 5% and 10% of all crashes in Iowa occur at commercial driveways. Most of these occur at arterials within municipalities. In recent years, nearly one-quarter of these crashes occurred in the Des Moines metropolitan area, making the area a prime candidate for improved access management. Case study research in Iowa has shown that access management is an effective highway safety tool: well-managed routes can be 40% to 50% safer than poorly managed routes. The Des Moines metropolitan area has many miles of older arterials that were constructed before access management was considered. This paper describes a cooperative effort of the Des Moines Area Metropolitan Planning Organization and the Center for Transportation Research and Education at Iowa State University to develop an access management study and program for the Des Moines metro area. The overall goal of the study is to use the knowledge developed to make improvements that will reduce access-related crashes. This project will also help local officials better consider access to avoid future safety and operational problems. The major task described in this paper was to identify and rank the Des Moines metro area's access management problems by using Iowa's GIS-ALAS database and other geospatial data. This process was developed to identify arterial segments in the metro area most promising for further investigation with regard to access management.
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