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Planning and Preliminary Design of Modern Steel Railway Bridges
Published in John F. Unsworth, Design and Construction of Modern Steel Railway Bridges, 2017
Train speed is governed by the relationship between curvature and superelevation. Railway bridge designers must have an accurate understanding of route geometrics to develop the horizontal geometry of the bridge, determine centrifugal forces, and ensure adequate horizontal and vertical clearances in through superstructures. The central angle subtended by a 30.5 m (100 ft) chord in a simple curve, or the degree of curvature, D, is used to describe the curvature of North American railroad track. Then the radius, R, and other simple curve data are as follows: R=360(30.5)2πD=1747.5Dm=5729.6Dft,
Curves
Published in W. Schofield, M. Breach, Engineering Surveying, 2007
Curves are designated either by their radius (R) or their degree of curvature (D°). The degree of curvature is defined as the angle subtended at the centre of a circle by an arc of 100 m (Figure 10.2).
Investigating the impact of correlation on system multimode reliability-based analysis of highway geometric design
Published in Transportmetrica A: Transport Science, 2021
Gabriel Lanzaro, Rushdi Alsaleh, Tarek Sayed
Speed prediction models are typically context-specific and depend on several factors that may influence driving behavior, such as geographic region, time of day, road geometry, and type of facility (Richl and Sayed 2006; Gong and Stamatiadis 2008; Bassani et al. 2016; Maji, Sil, and Tyagi 2018; Sil et al. 2019; Sil et al. 2020). Some of the differences in speed prediction models can also be attributed to different driving behavior in the considered regions (Sil et al. 2019; Sil et al. 2020). For horizontal curves, the degree of curvature was found to be the most significant parameter that affects vehicle speeds (Sil et al. 2019).