Automatic Horizontal Curve Identification and Measurement Using Mobile Mapping System

Abstract

This study presents an automatic method for horizontal curve identification and measurement using a mobile mapping system (MMS) with consideration of the impacts of vehicle wandering on the measurement. The hierarchical cluster model combined with the linear fit analysis achieved the automatic point of curvature (PC) and point of tangent (PT) station detection. The arc length method and chord offset method combined with the vehicle trajectory data were utilized for curve radius calculation. Finally, according to the adjacency patterns of the single curves, the types of curve were detected. A case study on a 9.756-km road section is provided, and on the test section, 21 single curves were detected and measured. Among them, 12 single curved segments were the simple curves, and nine single curved segments formed four reverse curves. A validation test based on the field measurement was conducted. The test results showed that the average errors for automatic PC/PT station detection, curve length measurement, and curve radius measurement were 2.15, 3.7, and 4.93%, respectively, which demonstrated that the presented method had a high accuracy for horizontal curve measurement. The significance of the proposed method was threefold. First, it solved the common problems of vehicle wandering on mobile survey. Second, it detected the curve types and the PC station of two adjacent single curves. Third, it had high accuracy, effectiveness, and automaticity, and can be used for roadway survey at network level.