Speed-flow models for Singapore downtown ring roads

• Main Author: Leo, Joseph Hee Chiang
• Other Authors: Wong Yiik Diew
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/140774
• Institution: Nanyang Technological University

This study seeks to derive the best fitting scalable speed-flow model based on data collected from downtown ring roads and concurrently examine the effect of road parameters, namely the number of lanes and lane width, on speed-flow models. Traffic data was collected from pedestrian bridges over 2 downtown ring roads, namely Scotts Road and Balestier Road, over weekdays between 0700h to 1500h over the morning peak, morning off-peak and afternoon peak periods. The extracted data was then modelled on several traffic speed-flow models. The model ultimately selected was the Generalised Drake model for its comparatively good fit across all lanes on both roads as compared to the Drake bell-curve, Greenburg’s, Greenshields’, Underwood’s, Polynomial and Quadratic models. Overall, having a greater number of lanes and does lead to a better development of steady state flow conditions. On the other hand, lane width does not significantly affect the fitting of the models.