Cover Image

Not for Sale



View/Hide Left Panel
Click for next page ( 14


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 13
13 The guidelines take the form of this final report and a web- very different purposes. Both safety and ecological approaches based interactive decision guide (www.wildlifeandroads.org). are necessary to effectively select the type, number, and loca- The project vision was to integrate safety and ecological tion of crossing facilities. When integrated, issues of both approaches to the problem of WVCs and the loss of ecological safety and landscape permeability are satisfied (Figure 1). permeability along roads. Identification of the gaps and pri- The goal of this project was to develop and integrate these two orities for both research and practice were used to develop a fundamentally different research approaches and incorporate state-of-the-art analysis that influenced the approach to the them effectively into the final interactive decision guide. research conducted for this project. Integration of two very different research efforts, safety and ecological, required a clear Structure of the Report focus and overt action to accomplish. Here is why: The safety analyses and the ecological analyses use essentially the same The project was divided into two phases. Phase 1 entailed basic data (i.e., carcass and animal collision data); however, an investigation of current relevant research and practices different auxiliary data are needed depending on the focus of concerning wildlife crossings (Tasks 1 and 2) and an identifi- the modeling and analyses, either safety or ecological. For ex- cation of significant gaps and priorities in both research and ample, for the safety modeling and analyses, right-of-way practice (Task 3). Phase 2 entailed five distinct research efforts data, commonly referred to as "geometrics," are coupled with to help bridge the knowledge gaps in research (Task 7) and de- AVC data to provide the bases for the rigorous empirical velopment of a web-based decision guide (Task 8). This report Bayesian approach. The primary objective for this modeling documents the research team's activities for the project. and analyses was safety. For the environmental modeling, Chapter 2 includes results for Tasks 2 and 3 from Phase 1. mapping, and analyses, off-road variables, coupled with either Chapter 3 covers the research conducted in Phase 2 in five sec- carcass or WVC data, provided the basis for the rigorous ap- tions. Section 3.1 discusses the application of reported WVC proaches used, although some ROW variables were included. data typically available in state DOT databases and investigates The primary objective for this modeling and analyses was how the application of two databases, reported WVCs and aimed at landscape permeability and healthy animal popula- carcass removals, can lead to different roadway improvement tions. In other words, the fundamental dataset (carcass data or decisions. Section 3.2 includes analyses of WVC data and animal collision data) was used with different variables for explores the limiting effects of roadkill reporting data due to Figure 1. Vision for NCHRP Project 25-27.

OCR for page 13
14 spatial inaccuracy. Section 3.3 investigates various WVC Each of these sections is organized into five subsections: hotspot identification (clustering) techniques that can be used (1) Introduction; (2) Research Approach: Methods and Data; in a variety of landscapes, taking into account different scales (3) Findings and Results; (4) Interpretation, Appraisal, and of application, from project-level to state-level analysis, and Applications; and (5) Conclusions and Suggested Research. transportation management concerns (e.g., motorist safety, Section 3.6 explains the distinctions among three of these re- endangered species management). Section 3.4 investigates the search methods: safety data analysis, accuracy modeling, and influence highways may have on the relative abundance of small hotspot modeling. mammals and how far any observed effect might extend into Chapter 4 provides a brief description of the web-based adjacent habitats. Section 3.5 explores whether the relationship interactive decision guide (www.wildlifeandroads.org) and between dispersal distances and home range size of mammalian instructions on how to use the guide. species can be used to develop scaling relationships to decide The References and appendices, which provide material on the placement of wildlife crossings that will help restore that supports the information in the chapters, are given at the landscape permeability across fragmented habitat networks. end of the document.