Improving Railroad Network Routing

Transcription

1 Improving Railroad Network Routing Roger Baugher, irector, Service esign April 13, 2007

2 The BNSF Network

3 The ar Routing Puzzle Hump Yards

4 Hump Yards One Routing Solution

5 Maintaining the Routing Rules A Local Perspective Traditional System Block from Memphis Block to Kansas ity General Merchandise Includes Thornton, elpaso, Plegrove, Marysvill, Mounkes, raig, Rocklin, Newcastle, Bowman, olfax, aphorn, Golrun, utflat, Alta, Towle, Midas, Blucanon, Emigap, isco, Troy, Norden, Truckee, Oroville, Elsey, Poe, Pulga, Merlin, amrodger, Belden, Virgilia, Paxton, Sprgarden, Quijct, Sloat, Blairsden, Portola, Hawley, Floriston, Verdi, Mogul, Lawton, hilcoot, Renjct, Scotts, oyle, Redhouse, Reno, Sparks, Vista, Hafed, Patrick, Herlong, Flanigan, Sanpass, Sano, Reynard, Wunotoo, lark, Thisbe... Total of 1823 Stations in this block Kansas ity Memphis

6 Maintaining the Routing Rules A Network Perspective incinnati Portsmouth

7 reating a New Paradigm Using A Shortest Path Algorithm Traditional Blocking esign manager must completely specify routing manually; computer adheres to specified routing Routing preferences hard coded into rules Routing changes, even minor local ones, may require network-wide revision of rules Algorithmic Blocking esign manager manually specifies routing options using skeletal block definitions; computer logic selects routes Routing preferences reflected in impedances Routing changes of any size may be implemented quickly and their impacts predicted with models

8 Setting Up Algorithmic Blocking E Leavenworth Waldron Kansas ity Block efinition From Kansas ity To E Leavenworth Any Traffic Block efinition From Kansas ity To Waldron Any Traffic

9 hanging Routes with Algorithmic Blocking A Set Valves (impedances) to Route Traffic as esired

10 Rule Maintenance Simplification with Algorithmic Blocking Stations overed Table Entries < 70 Traditional 550,000 + Algorithmic Blocking < 50,000

11 Real-Life Rerouting Problem 1996 Atlanta Olympics Normal Operating Plan for All Traffic To Macon Sheffield Knoxville hattanooga Linwood Atlanta Birmingham Macon

12 Real-Life Rerouting Problem 1996 Atlanta Olympics Olympics required rerouting of hazardous material Atlanta - Macon Sheffield Knoxville hattanooga Linwood Birmingham Atlanta X Olympics Macon

13 Real-Life Rerouting Problem 1996 Atlanta Olympics Manual iversion (SX) 6 months to install, then 1 month to restore Sheffield Knoxville hattanooga Linwood Birmingham Atlanta X Olympics Macon

14 Real-Life Rerouting Problem 1996 Atlanta Olympics AB iversion (NS) 1 person-day to plan and install Sheffield Knoxville hattanooga Linwood Birmingham Atlanta X Olympics Macon

15 Real-Life Rerouting Problem 1996 Atlanta Olympics AB iversion (NS) 1 person-hour to remove Sheffield Knoxville hattanooga Linwood Birmingham Atlanta X Olympics Macon

16 The Fundamentals of Algorithmic Blocking A yard A impedance Find blocks which can carry traffic (feasible blocks) Feasible blocks -- AB, A, B, Infeasible blocks -- A (weight restriction) Find lowest impedance route over feasible blocks Impedance AB = Yard A Impedance + Line AB Impedance + Yard B Impedance + Line B Impedance Impedance A = Yard A Impedance + Line A Impedance + Yard Impedance + Line Impedance Lower impedance route is chosen If a route is blocked, Algorithmic Blocking will find another, if one is available B yard B impedance yard impedance

17 Limitations of Algorithmic Blocking Routes across a sequence of blocks No consideration of trains and train connections No consideration of time No ability to consider capacity constraints Blocks do not have capacity constraints trains do apacity is a function of time, so failure to consider time prevents capacity planning Some traffic should be routed to minimize costs, others to minimize transit time

18 A Look at a Terminal A B ars At Yard A AB Algorithmic Blocking Next This AM PM pt 1200 Today B B pt 1800 Today pt 1200 Next ay Arrival Yard lass Bowl eparture Yard

19 A Look at a Terminal A B ars At Yard A TS AB Time-Space Solution This AM PM pt 1200 Today B B pt 1800 Today pt 1200 Next ay Arrival Yard lass Bowl eparture Yard

20 Another Look at the Network A AB Alone B This Next AM PM A Time-Space B

21 onvergence of Terminal and System Views S L L L M M M M B B B B Arrival Yard lass Bowl eparture Yard

22 onvergence of Terminal and System Views

23 Where o We Go From Here? Some form of algorithmic blocking in place or being implemented at four North American railroads. BNSF has a form of time-space algorithm without algorithmic blocking. Much work within and between railroads will be needed if railroads are to become more scheduled and their service more predictable.

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