01661268

Component

The AASHTO Highway Safety Manual (HSM) presents a variety of methods for quantitatively estimating crash frequency. The HSM predictive methods require the roadway network to be divided into homogeneous segments and intersections. The characteristics used to specify homogeneity vary depending on facility type, and could include number of lanes, shoulder width, traffic volume, median type, and a host of other characteristics. Despite the complexity and potential impacts of segmentation, there is a dearth of detail in documented procedures to determine homogeneous segment termini. To fill this void, this paper focuses on automation methods to determine appropriate roadway homogeneous segment termini for different facility types discussed in the HSM. Methods include a Microsoft Excel spreadsheet method using Visual Basic to subdivide roadway segments into homogeneous segments as well as an application for GIS platforms using multi-criteria dynamic segmentation. Both methods have been applied in support of an extensive HSM calibration project for South Carolina Department of Transportation. The paper also includes a case study using an actual roadway segment from South Carolina to demonstrate how the proposed spreadsheet procedure can identify appropriate homogeneous segments. The benefits of using these automated methodologies are summarized and recommendations for future research are discussed.

This paper was sponsored by TRB committee ANB20 Standing Committee on Safety Data, Analysis and Evaluation.

18-03826

English

9p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References (4) ; Tables

Classification; Crash characteristics; Crash rates; Geometric segments; Mathematical prediction

Highway Safety Manual

South Carolina

Data and Information Technology; Highways; Safety and Human Factors

Transportation Research Board Annual Meeting 2018 Paper #18-03826

TRIS, TRB, ATRI

Jan 8 2018 10:57AM