01659711

Component

Vertical profile and horizontal alignment of the road are used by the Highway Safety Manual to estimate the effect of grades and curves on the number of predicted crashes. Nevertheless, not always this resource is available to planners. In addition, large scale planning applications may render the conventional extraction of geometry parameters unfeasible. In this context, this paper proposes a general-purpose algorithm based on both Global Positioning System (GPS) or Geographic Information System (GIS) databases to extract geometry data from alignments and profiles for use in safety and operation analysis. Elevation data were obtained from an open digital terrain model and a Gaussian filtering technique was applied to the data to remove residual noise. In special, the horizontal curve component was designed to identify spiral transitions. To handle the additional complexity imposed by this feature, a genetic algorithm was coded to calibrate the proposed curve algorithm, so that curve radii, length and spiral transitions match real data. A testing two-lane highway facility was selected to evaluate accuracy of the proposed method. To achieve this objective, it was designed a computational application – Geographic Analysis Tool. The evaluation compared resulting curve information calculated based on common GPS and open source digital terrain model to as-built drawings obtained from 26 curves. All curves were identified by the algorithm, and all transitions correctly classified. The estimated radii values were similar to the real ones, which indicates that the proposed method could be used in different contexts at low cost.

This paper was sponsored by TRB committee ABJ60 Standing Committee on Geographic Information Science and Applications.

18-05636

English

8p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Algorithms; Geographic information systems; Geometry; Global Positioning System; Highway curves; Information processing; Two lane highways

Data and Information Technology; Highways

Transportation Research Board Annual Meeting 2018 Paper #18-05636

TRIS, TRB, ATRI

Jan 8 2018 11:26AM