4.1. SR 01-19-1999 - Laserfiche WebLink

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CAPACITY MODELING . Simulation Model Methodology Burlington Northern Santa Fe (BNSF) railroad is determining line capacity requirements for increased traffic by using a computer simulation model that replicates the operation of the railroad over a given territory. This model simulates a one-day period with twelve- hour startup and cool down periods on either side. Because of the one-day simulation period, a heavy traffic day is used to insure that results cover all traffic levels. The capacity of a given territory is defined by the number of trains that can be accommodated while maintaining the required schedules and priorities of each type of train involved. Improvements to capacity can come in the form of increased track and or turnout speeds, improved signaling systems, and the addition of sidings, crossovers, and or multiple tracks. Schedule changes can also be made to avoid conflicts between higher and lower priority trains, assuming that these changes can be done without impacting the customer requirements associated with the particular train. There are two key measures that BNSF is analyzing to determine the impacts of changes in train density and the improvements brought about by capacity additions: . Freight delay per 100 train miles . · Freight elapsed or transit time per 100 train miles These numbers are looked at in total for the system and can also be reviewed on a train class basis. Freight Only Capacity Modeling Simulation Analysis The BNSF completed three base simulations for the NCDA corridor including: · Year 1998 traffic level case (Scenario 1998) · Year 2003 traffic level with current operating practices case (Scenario 2003A) · Year 2003 with a revised operating plan which has intermodal train fueling and 1,000 mile inspection moved from the Northtown Yard to Minot (Scenario 2003B) The Year 1998 simulation included 123 various trains, switch moves, locals, and foreign line movements. Both Year 2003 cases added 20 trains. After review with BNSF, these increases appear reasonable. . Draft Commuter Rail Technical Feasibility Study December 1998 4-1 Capacity Modeling