INFORMS 2012 Shared Corridor Railway Maintenance Scheduling Brennan M. Caughron Graduate Research Assistant Rail Transportation and Engineering Center (RailTEC) University of Illinois at Urbana-Champaign

Outline FRA shared corridor research needs study Introduction and background Maintenance planning Strategic planning Tactical scheduling Integrated train and maintenance scheduling SRC research needs

Project Description: New high speed rail (HSR) developments in the U.S. need to address technical challenges of shared rail corridors in the North America rail environment The objectives of this project are to identify shared rail corridor technical challenges, existing and on-going research, knowledge gaps and research needs INVESTIGATING TECHNICAL CHALLENGES AND RESEARCH NEEDS RELATED TO SHARED CORRIDORS FOR HIGH-SPEED PASSENGER AND RAILROAD FREIGHT OPERATIONS Research Sponsor: BROAD AGENCY ANNOUNCEMENT BAA Research and Demonstration Projects Supporting the Development of High Speed and Intercity Passenger Rail Service Impact on the Railroad Industry: Reducing the operational and program deployment risks associated with shared rail corridors Identification of critical areas to address in planning new HSR systems Expediting the process of developing efficient and safe HSR shared corridors with better prioritization in planning

Shared-Use Corridor Operating Configurations Shared track: tracks shared between passenger and freight or other service. Shared right of way (ROW): dedicated high-speed passenger tracks separated from freight or other service tracks up to 25’ Shared corridor: dedicated high- speed passenger tracks separated from freight or other service tracks by ’ High-speed rail service Freight or conventional passenger rail service Adjacent track centers >25’ ≤ 200’ Adjacent track centers ≤ 25’ Shared track & shared ROW Shared corridor

Shared Corridor Categories Safety technology and operating practices Rail infrastructure and equipment Economic and institutional issues Planning and operations Infrastructure upgrade prioritization Rail capacity planning Train scheduling patterns Passenger train schedule reliability Maintenance-of-way scheduling

Railway Periodic Inspection Inspection activities occur on regular intervals depending on quality (class) of track Inspection events Visual inspection monthly to 1-3 times per week (speed, track function, traffic) Rail flaw detection 2 yearly or before 40MGT (with passenger traffic) Gauge restraint measurement system annually for classes 8 and 9 Automated track geometry 1-2 yearly up to twice every 120 days Joint bar flaw detection Ground penetrating radar Machine vision systems Personnel and equipment must usually occupy track to perform inspection (some exceptions)

Railway Periodic Maintenance Track is taken out of service for maintenance to occur Operation on adjacent tracks can be impacted by maintenance activities Activities occur on intervals based on cumulative traffic or time Categories of maintenance work Rail relay Curve gauging Tie replacement Ballast cleaning Shoulder ballast cleaner Undercutting Surfacing System high-speed Spot surfacing Track renewal Bridge maintenance

Modeling Maintenance Scheduling Numerous individuals have applied optimization techniques to problems related to planning and scheduling railway maintenance Model categories Strategic planning Tactical scheduling Maintenance scheduling within existing schedule Integrated train and maintenance scheduling

Strategic Maintenance Planning Long term planning horizon (year) Large time increment (week) Schedule work crews to specific projects on the network Generally preventative (rail, ties, ballast) vs. reactive maintenance (fixing slow orders) Considers various network constraints Number and type of work crews Work crew location constraints Multiple projects on each network segment Benefits of maintenance blitz strategies Longer term disruption of rail traffic Precedence relationship between activities Weather or seasonal constraints

Strategic Maintenance Planning A C D B E F Network ? ? ? ? ?

Strategic Planning - Previous Work Grimes (1995) Genetic algorithm Track surfacing planning Track quality, degradation rate, various costs Budai et al. (2006) Preventative maintenance scheduling problem (PMSP) Minimize total track possession cost Considers one network segment Gorman et al. (2010) Maintenance production gang scheduling Minimize labor, equipment, repositioning/travel costs Labor agreements, precedence relationships, early start/late finish constraints

Strategic Planning - Previous Work Pouryousef et al. (2010) Refined PMSP from Budai Simultaneous planning of several segments Minimize track possession cost, maintenance cost, and penalty for performing work too early Peng et al. (2011) Minimize travel costs of production gangs (travel cost more variable than relative fixed cost of performing work) Weather, network disruption, activity precedence constraints included Methodology integrated into maintenance planning process of a class 1 railroad

Tactical Maintenance Scheduling Short term planning horizon (weeks or days) Small time increment (hours) Planning for one or several lines vs. network Scheduling maintenance activities into existing traffic pattern Train schedule typically adopted before maintenance schedule Not able to reschedule some types of rail traffic Passenger (+- minutes) Intermodal (+- hours) Manifest (+- hours) Delay costs for different traffic types Productivity losses for maintenance crews with interrupted or split work windows Limited number of crews

Tactical Maintenance Scheduling Time Distance 1 2 3

Shared ROW with High Speed Rail Time Distance Existing RR New HSR High speed trains 1 2 3

Previous Work Higgins (1998) Schedule maintenance activities and crews in an existing rail traffic pattern Decision support tool for operation and maintenance managers Activities considered Inspection Cross ties Rail (replacement and grinding) Ballast cleaning Track surfacing Case study line (302 km, 45 sidings) Manually constructed maintenance schedule 7.4% increase in activity finishing time 18% increase in train and maintenance delay

Integrated Train and Maintenance Scheduling Maintenance activities and train schedules planned simultaneously Objective function: minimize total cost of train delay and maintenance activities North American operating environment Unscheduled trains (bulk commodities) Scheduled trains (passenger, intermodal, manifest) Long trains Long shipment distances (2,000+ miles) European operating environment Scheduled trains (freight and passenger) Meet and pass planning Temporal separation of traffic types Integrated train and maintenance scheduling may have limited application in the N. American operating environment

Previous Work Albrecht et al. (2010) Problem space search (PSS) meta-heuristic Simultaneous scheduling of maintenance activities and rail traffic Minimize total delay to rail traffic and maintenance crews Considered additional metric – delay experienced by worst performing train (better consideration of distribution of delays) Applied to case study line Total delay reduced 17% vs. manual schedule Maximum delay reduced 34%

Shared Corridor Research Needs Strategic planning Passenger traffic delay constraints related to network and seasonal conditions Tactical scheduling Delay cost for different train types Cost of lost maintenance productivity in interrupted or split windows Threshold for integrated rail traffic and maintenance planning Threshold for temporal separation (maintenance at night, rail traffic during the day) Tactical scheduling with stochastic train and maintenance events (longer planning horizon, more uncertainty)

Questions? Brennan M. Caughron