Interdicting Tradeflow on the U.S. Rail Network

1. Interdicting Tradeflow on the U.S. Rail Network LTC Brian Axelsen MAJ Steve Jones

2. U.S. Rail Network • Vital to moving large amounts of goods between large population centers. • a network of more than 140,000 miles • 43 percent of intercity freight volume • Shippers would pay $69-95 billion more per year if all freight moved by rail were shifted to truck • On average, railroads are four times more fuel efficient than trucks. Source: http://www.aar.org - Association of American Railroads

3. US Rail Network Class 1 Rail Network

4. Model Scenario • Determine the impact of a “dirty bomb” attack on the tradeflow between the two largest U.S. cities and the rest of the country. • Multi-commodity (NYC and Los Angeles) • “New York” and “LA” commodities • Two of the most populous cities and busiest ports • Demand from each node is the tradeflow between that node and NYC and LA • Supply is sum of all demand for each commodity

5. Gravity Model • Basic theoretical model for trade • Used to evaluate NAFTA and WTO

6. Model Scenario • Nodes: 50 largest Metropolitan Statistical Areas (MSA) and 20 key rail intersections. • Edges: Represent multiple rail lines between two nodes. • Cost = $1 per tradeflow unit per mile • Very large capacity

7. US Rail Network

8. US Rail and Abstract Networks 46 42 47 30 43 41 29 1 21 62 61 52 2 51 12 11 22 15 3 35 40 13 56 4 48 23 57 49 59 36 31 14 60 24 16 32 5 44 39 17 58 53 6 50 34 18 38 7 19 54 45 8 25 20 9 37 64 27 28 26 55 10 33

9. Abstract Network 46 42 47 30 43 41 29 1 21 62 61 52 2 51 12 11 22 15 3 35 40 13 56 4 48 23 57 49 59 36 31 14 60 24 16 32 5 44 39 17 58 53 6 50 34 18 38 7 19 54 45 8 25 20 9 37 64 27 28 26 55 10 33

10. Measure of Effectiveness Total economic cost of the supply and demand model for tradeflow. • Shipping costs along usable edges • Cost of unsatisfied demand • Both NYC and LA commodities

11. Operator’s/Attacker’s Problem • Operator wants to satisfy all demand for each commodity at the minimum cost • Attacker uses dirty bombs to maximize the cost of tradeflow between the two largest population centers and the rest of the country. • Attacking an edge represents the incapacitation of the rail network between two MSA’s. • Additional Constraint to Attacker: Edges originating from a supply node cannot be attacked.

12. Operator Resilience Curve Seattle Isolated D.C Isolated Boston Isolated Detroit Isolated Pittsburg Shipping Restricted

13. 1 Attack No City Isolated; increased cost to meet demand.

14. 2 Attacks Detroit Isolated

15. 3 Attacks Washington D.C Isolated

16. 4 Attacks Washington D.C and Virginia Beach Isolated; there is now “excess” supply in NY.

17. 5 Attacks No City Isolated; significantly increased cost; ¼ of supply cannot leave NY.

18. 6 Attacks No City Isolated; significantly increased cost; ¼ of supply cannot leave NY.

19. 7 Attacks Seattle Isolated; significantly increased cost; 1/4 of supply cannot leave NY.

20. 8 Attacks Boston Isolated; significantly increased cost; 1/3 of supply cannot leave NY.

21. Model Extension • Removed constraint that arcs coming from supply nodes cannot be attacked. • New York isolated first: consistent with Gravity Model • Solutions are not nested • Costs increase by orders of magnitude upon isolation of a supply node • Consistent with securing supply nodes

22. Open Ended Analysis • Total Economic activity: All nodes have supply to and demand from all other nodes. • All Port Economic activity: All nodes with a port have supply to and demand from all other nodes. • Split nodes in two to model attacking a city’s population as well as the network (Multi-objective model for the attacker) • Adjust capacity based on number of nodes between two cities.

23. Summary and Conclusions • Overall Resiliency of Rail Network • High physical capacity, especially east of Mississippi • No single point of failure • No point of extreme vulnerability: Solutions not nested. • Greatest increase in cost incurred by isolating a transportation hub, not a city.