Geometric Alignment of Western Bypass Road, Federal Capital Territory, Abuja, Nigeria

Abstract

This study, titled "The Geometric Alignment of Western Bypass, Federal Capital Territory, Abuja", focuses on the geometric improvement of the Western Bypass, a critical road in Abuja, Nigeria's Federal Capital Territory (FCT). The study involves creating road alignment, plotting alignment profiles using coordinates (easting and northing), analyzing cross-sections and elevations, and conducting various analyses to select the optimal alignment while adhering to design standards. Geometric Alignment in highway engineering enhances road safety, traffic efficiency, and overall performance. However, manual geometric design is often inconvenient, time-consuming, and prone to costly errors. The Western By-Pass, a bituminous road, has experienced significant deterioration due to constraints such as traffic growth, inadequate geometric features, and environmental conditions. The primary goal of this research is to propose an improved geometric alignment that optimizes safety, efficiency, and comfort while minimizing environmental impact. The study evaluates existing road conditions, assesses traffic volume and speed variations, and proposes geometric improvements such as shoulder widths, lane widths, and horizontal and vertical alignment. The research methodology includes the use of computer-aided design (CAD) software such as AutoCAD Civil 3D, and Blender to ensure precision and efficiency in the design process. The specific objectives of the research include determining the existing highway capacity, speed variations, and traffic volume, and proposing a geometric alignment that adheres to national design standards. The existing road spans 5.8km and has a design speed of 68km/h. The study evaluated the roads the roads' horizontal and vertical alignments, cross sections, and other geometric features to ensure smooth directional changes and improved traffic flow. The analysis included calculating cumulative cut volume, filled volume, and net volume to assess the road's current condition and propose necessary improvements. The findings aim to optimize the roads' performance, minimize environmental impact, and ensure more efficient transportation for users.