Blocking Capacity and Level of Service in Railway Hump Classification Yards

The objective of this research is to determine the fundamental hump classification yard capacity relationship between level of service and throughput volume of railcars as a function of the number of blocks assembled in the yard. In designing a train plan for a railway network, one decision is to determine the number of blocks to be handled by each train and the number of blocks to be assembled at each classification yard while maintaining a certain level of service. Increasing the number of blocks per train typically increases the number of blocks to be made at classification yards. A trade-off exists as terminal managers can more effectively operate their facilities by making fewer larger blocks. Meanwhile, the overall line-haul network operates better if each yard is handling a greater number of smaller blocks; increasing routing options and shortening connection times allows for optimized car trip plans. This research will investigate the terminal aspect of this trade-off by designing a factorial experiment to determine the relationship between yard throughput volume, the total number of blocks processed and the level of service. The number of inbound and outbound trains will be held constant, with the number of blocks per train varied accordingly. The experiments will be conducted with the Hump Yard Simulation System (HYSS) tool and six-week car files based on actual railroad operations. Following this initial analysis, the factorial experiment will be expanded to include other yard operational factors that may influence yard capacity. Later analysis of different rail yard facilities will examine the influence of train arrival rate, yard layout and overall yard configuration on the developed capacity relationship. It is anticipated that the cumulative results of this research will yield a basic parametric relationship for yard capacity. This relationship can be used by industry practitioners to develop more effective train plans, manage classification yard operations and plan investments in hump yard capacity.


    • English


    • Status: Active
    • Contract Numbers:



    • Sponsor Organizations:

      Office of the Assistant Secretary for Research and Technology

      University Transportation Centers Program
      Department of Transportation
      Washington, DC  United States  20590
    • Principal Investigators:

      Dick, Tyler

    • Start Date: 20160615
    • Expected Completion Date: 20180615
    • Actual Completion Date: 0

    Subject/Index Terms

    Filing Info

    • Accession Number: 01613508
    • Record Type: Research project
    • Source Agency: National University Rail Center (NURail)
    • Contract Numbers: DTRT13-G-UTC52, NURail2014-UIUC-R15
    • Files: UTC, RiP
    • Created Date: Oct 20 2016 3:18PM