The intersection delay, representing the levels of service, is the major performance measure of a signalized intersection. The most popular traffic software packages such as Highway Capacity Software (HCS) and Synchro provide detail delay calculation, level of service analyses, and queue analyses. However, the effects of available queue storage lengths of turn lanes on intersection delay were not addressed in the HCS and Synchro Version 5. The software packages reported identical results of lane group delays, regardless of the inputted turn lane queue storage lengths. Recently, Synchro Version 6 started to introduce a new series of traffic analysis to address how queue can reduce capacity and increase delay through spillback, starvation, and storage blockage between lane groups. The focuses of this study are to examine the storage blockage problem for left-turn lanes at signalized intersections, and provide potential strategies to reduce traffic congestion and improve traffic safety. This paper first examines the effects of inadequate left-turn queue storage lengths on intersection delay. Then, it describes the importance of addressing left-turn lane storage blockage problems. The methods to measure the performance of signalized intersections with inadequate left-turn lane queue storage lengths are then presented. This paper develops effective strategies in order to minimize negative traffic operational impact resulted from inadequate left-turn lane length. These strategies are illustrated by examples with microscopic simulation results from the SimTraffic. The paper also provides transportation professionals potential strategies to alleviate traffic congestion and safety problems caused by inadequate left-turn lane storage lengths at signalized intersections.

  • Availability:
  • Supplemental Notes:
    • Full conference proceedings available on CD-ROM.
  • Corporate Authors:

    Institute of Transportation Engineers (ITE)

    Washington, DC  United States 
  • Authors:
    • Lin, P-S
    • Kou, C-C
  • Conference:
  • Publication Date: 2004


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 15p

Subject/Index Terms

Filing Info

  • Accession Number: 00981494
  • Record Type: Publication
  • ISBN: 0935403876
  • Files: TRIS
  • Created Date: Nov 3 2004 12:00AM