Safety Effectiveness of High-Speed Expressway Signals, 2005

The safety benefit of signalizing intersections of high-speed divided expressways is considered. Analyses were conducted on 50 and 55 mph and on 55 mph only intersections, comparing unsignalized and signalized intersections. Results of the 55 mph analysis are included in this report. Matched-pair analysis indicates that generally, signalized intersections have higher crash rate but lower costs per crash. On the other hand, before-and-after analysis (intersections signalized between 1994 and 2001) indicates lower crash rates (~30 percent) and total costs (~10 percent) after signalization. Empirical Bayes (EB) adjusted before-and-after analysis reduces estimates of safety benefit (crash rate) to about 20 percent. The study shows how commonly used analyses can differ in their results, and that there is great variability in the safety performance of individual signalized locations. This variability and the effect of EB adjustment are demonstrated through the use of innovative graphics.

Iowa Historic Property Study of the Zeman Barn, 2009

The Zeman Barn (86-00028) is an early twentieth-century example of a gothic roofed barn and is part of the Zeman Farmstead located along U.S. Highway 30 in Otter Creek Township (Township 38N, Range 14W), Tama County, Iowa (Figures 1 and 2). The farmstead was initially evaluated in a reconnaissance architectural survey conducted in 1998 by The Louis Berger Group, Inc (Berger). An intensive architectural survey of the property by Berger’s Principal Architectural Historian, Martha H. Bowers, evaluated the farmstead as not being eligible for listing in the National Register of Historic Places (National Register) but noted that the barn appears to be eligible for listing in the National Register under Criterion C (Bowers 1998). At the request of the Iowa Department of Transportation, Berger completed the recordation project to provide a documentary record of the Zeman Barn in accordance with the guidelines set forth by the Iowa State Historic Preservation Office regarding historic property studies for barns. Background research for this project was conducted in September 2008 and April 2009. The property was inspected and photographed in May 2008. Information on the property was gathered through background research, interviews with Zeman family members, field investigation, and photo documentation. Historical maps of the project area were used to collect data necessary for developing regional and local historic contexts. The research for this report was conducted at the Tama County Courthouse and the Tama County Historical Museum Genealogical Library, both in Toledo. Much of the background research for the project was conducted by Camilla Deiber and Michael Dulle. Ms. Deiber also prepared the photographic documentation, plan drawings, and the graphics used in this report. Mr. Roger L. Ciuffo conducted interviews with Zeman family members and wrote this report.