Modelling Horizontal Highway Alignment From Points Cloud Topographic Surveying Data

Optimising Highway Corridor and Alignment Creation

Abstract

Context and background

A Horizontal Highway Alignment gives the 2-Dimensional orientation of a highway. It is constrained to geometric parameters derived from highway surveying data. The state-of-the-art highway surveying, gradually shifts from conventional (single point) surveying to points cloud surveying, increasing data collection efficiency, saving costs and enhancing understanding of terrain surfaces. Unfortunately challenges surveying data collection corridor delineation and lacks standardized operating procedures. Thus, oftentimes, it results into collecting very large unused bulk of data and non-regulated standard procedure of operations.

Goal and Objectives:

To create a model for Horizontal Highway Alignment creation from points cloud to assist optimisation of highway corridor and semi automation of alignment creation. This is to optimise highway corridor limits through which surveying data collection should be limited to and trying to constrain Horizontal Highway Alignment to follow completely with very little deviations

Methodology:

The model was developed using C# programming language on Visual Studio Independent Development Environment. Only decision points and design velocity adjusted the rest of the highway parameter to compliance. Other constant inputs were; the coefficient of friction, grade and perception time values to complete the modelling process.

Results:

From four experiments, maximum curve rotation was -0°59’18.81”, curve length discrepancy ranged from 0.04m to 0.095m and precision of extremities for curvature points positions was less than 0.07m.  

The results, show that the model developed, creates the HHA fulfilling the standard requirement with very high surveying precision and may be used for highway alignment modelling.