Capacities of cross-junction and roundabout in Nanyang Technological University

• Main Author: Choo, Ping Ling.
• Other Authors: Fan Shing Leung, Henry
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Civil engineering::Transportation
• Online Access: http://hdl.handle.net/10356/16309
• Institution: Nanyang Technological University

The capacity of a roundabout is a function of the capacities of the individual entry arms. The capacity of each arm is the maximum inflow when the traffic flows at the entry is able and sufficient to cause continuous queuing in its approach road. According to FHWA [2000], the capacity of a roundabout entry is dependent on two main factors; the circulation flow on the roundabout which conflicts with the entry flow and the basic geometric elements of the roundabout. This study aims to compare the effectiveness of the cross junction and roundabout within the area of Nanyang Technological University (NTU). Increasing numbers of students and staff in NTU has prompted the increase of the number of road users within NTU. Therefore, type of road intersection used is of concern as efficiency of transportation system may diminish road congestion and reduce time lagging for road users. The comparison is made between cross junction near NTU Graduate Hall and roundabout near NTU School of Art, Design and Media. The assessment of the performance comparison between these two intersections was made based on their performance in terms of queue length and delay time cause. The results of the comparison showed that the roundabout has shown less performances than the cross junction in terms of capacity and efficient function. This is understood as there is perceived privilege available at cross junction type of intersection and not available at roundabout type of intersection, that is, major road as the priority in the intersection, while the roundabout sustains equal treatment to all its legs. Therefore, roundabout type of intersection has to be the less considered type of road intersection for future use or amendment choice.