01334638

Component

Several states have already begun to prepare data sets for use with new advanced safety analysis tool, Highway Safety Manual and Safety Analyst, and one of the overarching concepts in these safety processes is the identification of homogeneous segments and intersections. Homogeneous, with respect to a roadway segment, implies that all of the characteristics of that segment are the same. The characteristics used to specify homogeneity could include number of lanes, shoulder width and type, traffic volume, median presence and type, and a host of others. The idea of homogeneous segments may or may not easily mesh with existing state GIS databases depending on what type of segmentation process is used by individual states. Additionally, segmentation has very real impacts with respect to biasing the outcomes of safety analysis, especially when considering traditional site selection methods such as rates and frequencies. However, segmentation also plays an important role in advanced methods and potentially impact the validity of the results. The overarching goal of this research is focused toward aiding the new user of advanced safety analysis methods with database development and maintenance activities. In particular, the results of this research depict various issues related to choice of segmentation method and approaches for generating homogeneous segments. First, the results of a simple length based segmentation approach will be used to show how segment length can skew the results of a safety analysis. Second, the results of multiple segmentation approaches using varying levels of sensitivity for roadway data element data sensitivity and varying number of included elements will be compared. Finally, recommended strategies are presented for data management and segmentation for use by early adopters of advanced methods.

01329018

11-4156

English

19p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (6) ; Photos; References (15) ; Tables (4)

Analysis; Crash data; Databases; Geometric segments; Highway safety; Inventory; Safety

Model Inventory of Roadway Elements; Model Minimum Inventory of Roadway Elements; Model Minimum Uniform Crash Criteria

Data and Information Technology; Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure

Transportation Research Board Annual Meeting 2011 Paper #11-4156

TRIS, TRB

Feb 17 2011 6:46PM