VEHICLE MOVEMENTS AND INTERACTIONS AT ROUNDABOUT INTERSECTIONS

The paper examines the circulating paths of vehicles at roundabouts and also methods of evaluating capacities of such layouts. The work of Al-Alawi in investigating the lateral placement of circulating vehicles is detailed. In this work time-lapse cine recording techniques were employed to obtain details of vehicle paths and gap acceptance operations. This observed merging decision-making was classified and mean lag and standard deviation determined. Using the results of this analysis a computer model of traffic flow at a roundabout intersection was developed. The model can be used to simulate a roundabout with up to five approaches with a maximum of five lanes on each approach. The object of the model was to investigate traffic flow at roundabouts when for short periods demand exceeds capacity. It is considered that the model is capable of realistically simulating traffic behaviour at roundabouts when predictions of vehicle paths can be made within the circulating area. (TRRL)

• Corporate Authors:

  Institution of Civil Engineers

  One Great George Street, Westminster
  London,   United Kingdom  SW1P 3AA
• Authors:
  • SALTER, R J
  • Al-Alawi, J A
• Conference:
  • Institution of Civil Engineers, Proceedings, Pt2
• Publication Date: 1982-12

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 815-823
• Serial:
  • Volume: 73
  • Issue Number: PT2

Subject/Index Terms

• TRT Terms: Computer programs; Gap acceptance; Highway capacity; Lateral placement; Layout; Mathematical analysis; Mathematical models; Motion; Motor vehicles; Roundabouts; Simulation; Time lapse photography; Traffic circles; Traffic congestion; Traffic flow; Traffic surveys
• Uncontrolled Terms: Interaction; Moving vehicles
• ITRD Terms: 6471: Analysis (math); 643: Capacity (road, footway); 2885: Layout; 6473: Mathematical model; 438: Roundabout; 9103: Simulation; 8645: Software; 671: Traffic flow
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; I21: Planning of Transport Infrastructure;

Filing Info

• Accession Number: 00370837
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Mar 31 1983 12:00AM