Field Evaluation of Timber Preservation Treatments for Highway Applications Final Report, December 2007

Timber material repair and replacement cost for timber bridges is a considerable expense to highway agencies in Iowa, especially to county road departments. To address these needs, the objectives of this investigation was to study the field effectiveness of various treatment alternatives used on Iowa roadway projects and to determine if the current specifications and testing are adequate for providing proper wood preservation. To satisfy the research needs, the project scope involved a literature review, identification of metrics, questionnaire survey of Iowa counties, onsite inspections, and a review of current specifications and testing procedures. Based on the preservative information obtained, the following general conclusions were made: Copper naphthenate is recommended as the plant-applied preservative treatment for timber bridges. Best Management Practices should be followed to ensure quality treatment of timber materials. Bridge maintenance programs need to be developed and implemented. The Iowa Department of Transportation specifications for preservative treatment are the regulating specification for bridges constructed with state or federal funding in Iowa and are also recommended for all other bridges.

Roadway Alignments as Assets: Evaluating Alternatives for Valuing Major Highway Corridor Rights of Way Final Report December 2010 Sponsored

In most highway asset management exercises, real estate used in alignments is considered to be an asset class that does not depreciate. Although the treatment of right of way assets as non-depreciable real property may be appropriate as an accounting exercise, the fact is that the real estate contained in transportation corridors can in fact lose value from a traffic service point of view. Such facilities become functionally obsolete in that they no longer serve the purpose that was intended when they were planned, designed, and built. This report is intended to begin a discussion of the topic of how highway alignments ought be valued as assets as opposed to how they generally are valued, at either book value or replacement value, given it can be shown that some highway alignments do in fact depreciate in value.