INFORMS 2012Shared Corridor Railway Maintenance Scheduling

Brennan M. CaughronGraduate 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-2010-1

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 25-200’

High-speed railservice

Freight or conventional passenger rail service

Adjacent trackcenters >25’ ≤ 200’

Adjacent trackcenters ≤ 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

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Network

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Projects

7

Crews

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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

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Shared ROW with High Speed Rail

Time

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Existing RR

New HSRHigh speed trains

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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. Caughronbcaughr2@illinois.edu