National Academies Press: OpenBook

Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner's Guide (2009)

Chapter: Appendix 9 - Shared-Track Configuration and Operational Alternatives

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Suggested Citation:"Appendix 9 - Shared-Track Configuration and Operational Alternatives." National Academies of Sciences, Engineering, and Medicine. 2009. Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner's Guide. Washington, DC: The National Academies Press. doi: 10.17226/14220.
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Suggested Citation:"Appendix 9 - Shared-Track Configuration and Operational Alternatives." National Academies of Sciences, Engineering, and Medicine. 2009. Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner's Guide. Washington, DC: The National Academies Press. doi: 10.17226/14220.
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Suggested Citation:"Appendix 9 - Shared-Track Configuration and Operational Alternatives." National Academies of Sciences, Engineering, and Medicine. 2009. Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner's Guide. Washington, DC: The National Academies Press. doi: 10.17226/14220.
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107 A P P E N D I X 9 Shared-Track Configuration and Operational Alternatives Train Control System Description: Infrastructure Option Operating Regime Under temporal separation, automatic train stop isn’t strictly necessary. Access can be restricted by an interlocked switch and derail, protected by electric locks and points indicators. A special software program is required on the CTC system console for the diurnal “transfer procedure” that enables the dispatcher to “unlock” the freight connection and locks the light rail yard at the prescribed time. Intrusion detection may or may not be necessary depending upon the freight activity and/or clearances. With spatial separation, automated train stops are required for any diamonds. This option enables freight to operate at all times of the day. The automatic train stop (ATS) system on the LRVs protects crossings of freight trains over the switch diamonds. The ATS would be a two-aspect system that initiates the emergency brake should an LRV fail to stop. The train stop would be located at braking distance from the fouling point of the diamond crossing. Intrusion detection may or may not be necessary depending upon the freight activity and/or clearances. For single concurrent shared- track, a cab signal system with automatic speed control would be required on both freight and passenger trains. The line would be signaled and maintained for maximum passenger and freight speeds of 60 mph and 30 mph respectively, requiring a three- aspect system that regulates speed and initiates braking prior to STOP signals. The system would supervise train speeds and enforce maximum speeds. It could be transponder based or coded-track circuit based. Intrusion detection may or may not be necessary depending upon the freight activity and/or clearances. Note the physical configuration, track layout (single and double), grade crossings, structures, alignment, grades, route environment (e.g. downtown or suburban), sidings, crossovers, freight customer facilities, The requirements listed in Option 1 apply. However, in this scenario a dedicated track is provided for freight service. Fail-safe train separation (automatic train stop) is only provided at diamond crossings between freight and light-rail The requirements listed in Option 1 apply. The proposed concurrent shared-track system features 15 minute peak headways and half-hourly off-peak service. Light rail tracks may extend to the downtown district via the stations. Train Control System – e.g. Centralized Traffic Control (CTC) is provided, with train movements controlled by wayside block and interlocking signals. All freight connections to passenger tracks are interlocked with the signal system, and are protected by derails. At siding connections, the predominant danger is unattended freight cars rolling onto the main line – and not a moving freight train that has exceeded movement authority. track. Depending upon local geometric constraints, the freight track may need to be reconstructed completely to make room for stations and other passenger facilities. The track roadbed may also need to be widened. local street network. Simple island-platform stations provide passenger ingress and egress. A cab signal system protects against freight-light rail collisions. Estimate the end-to-end trip time and allow the “turn-time” to change ends at the terminal station to calculate hourly round-trip car cycles. Passing sidings may be required for flexibility. 1 Strict Temporal Separation Track 2 Spatial Separation 3 Concurrent Single Track 4 Concurrent Double For concurrently shared double-track, the same Option 3 signal system would be required. Under this scenario, a freight train could pass an opposing light rail train at speed on adjacent tracks, increasing the risk of shifted-lading strikes. On a single-track system, close clearances between two tracks may be less common. Intrusion detection may or may not be necessary depending upon the freight activity and/or clearances. The requirements listed in Option 1 apply. The transit system would operate every 15 minutes in the peak, and 30 minutes off-peak. The double-track allows increased train frequencies without new construction and provides better passenger on-time performance. The main motivations of double tracking are threefold: 1. More reliable passengerservice; 2. Greater flexibility in service planning for passengers and freight services; 3. Greater passenger safety.

108 Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner’s Guide Option Operating Regime 1 Strict Temporal Separation Passenger Operations & Timetable Identify operations via track shared with the freight carrier and the distance traveled over shared-track. Note the time of passenger service operations, i.e. hours each weekday from start to finish. Describe the temporally separated shared- track, e.g., is it primarily single track with any passing sidings to provide for bi-directional passenger operations. Prepare a train schedule. Typically a service may operate at 15 minute headways during the daily peak service hours and 30 minute headways during the off-peak. This provides the total daily weekday trips in each direction, and peak hour trips. This will establish the number of trains in operation during peak and off-peak service. Passenger Distribution Identify the heaviest ridership period in the shared-track area on any single train during the typical service day. Establish any train meets during the rush-hour. Estimate ridership during the midday off-peak period by time of day, segment and direction. Calculation of the passenger loading of trains is a key input to the risk assessment. Ridership varies substantially by time of day. Under this option the incremental risk of adding freight service is influenced by off-peak train occupancy, so knowing hour by hour train occupancy is necessary. 2 Spatial Separation The information requirements of Option 1 apply. Along side the freight track there is now a dedicated transit track. It is primarily single track with two passing sidings to provide for bi-directional passenger operations. The light rail passenger service differs from Option 1 by having extended service hours earlier in the morning and later into the night. The passenger service can operate 20 hours each weekday from 5am to 1am the next morning. Weekend services can span the same hours but may have longer headways. As an example, service can operate with 15 minute headways during the peak service hours and 30 minute headways during the off peak, except at late nights when the headway is hourly. The information requirements for Option 1 apply. However, ridership for Option 2 captures additional early morning and late night riders. Overall passenger mobility is increased with ridership above temporal separation because of the extended hours. Therefore the ridership calculations will vary. 3 Concurrent Single Track The information requirements of Option 1 apply. The light rail passenger service differs from Option 1 by having extended service hours earlier in the morning and later into the night. The passenger service can operate 20 hours each weekday from 5am to 1am the next morning if it wishes. Weekend services can span the same hours but may have longer headways. As an example, service can operate with 15 minute headways during the peak service hours and 30 minute headways during the off peak, except at late nights when the headway is hourly. The information requirements for Option 1 apply. The assumption for rider distribution for Option 3 remains the same as Option 2, since the service headway and the span of service remains unchanged. Therefore the ridership calculations will vary. Freight trains will not operate during the passenger peak periods. During the off-peak period, freight trains will serve customers en-route, using the sidings to allow half-hourly passenger services to ‘get by’ as appropriate. 4 Concurrent Double Track The information requirements of Option 1 apply. The light rail passenger service differs from Option 1 by having extended service hours earlier in the morning and later into the night. The passenger service can operate 20 hours each weekday from 5am to 1am the next morningif it wishes. Weekend services can span the same hours but may have longer headways. As an example, service can operate with 15 minute headways during the peak service hours and 30 minute headways during the off peak, except at late nights when the headway is hourly. The information requirements for Option 1 apply. Passenger distribution for Option 4 is the same as Option 2. Therefore the ridership calculations will vary. A full major investment analysis would determine whether the incremental benefit of double-track justifies the incremental cost of its construction. In essence, when one track segment is blocked out to serve a freight customer, the passenger service ‘sees’ an additional ‘single track’ section. These constraints impact passenger scheduling, but not as severely as it does with single track. and gates. Low-volume or private crossings can be protected by flashers and bells if authorized by State (see note 2). All signal and communication systems, track and structures are designed, constructed inspected and maintained to FRA standards. NORAC (see note 1) operating rules are used for all freight and passenger movements. Track is maintained to FRA Class III. Grade crossing warning systems should be upgraded to MUTCD standards and be equipped with flashers, bells, Infrastructure

Shared-Track Configuration and Operational Alternatives 109 Option Operating Regime 1 Strict Temporal Separation 2 Spatial Separation 3 Concurrent Single Track 4 Concurrent Double Track system arrangement, few additional freight benefits are accrued (over the “null” condition). Both the good and bad aspects of the status quo are maintained. The fully concurrent track sharing affords much more flexibility to the freight carrier. If the traffic pattern should change, then freight train starts can be adjusted. Freight trains can operate any time except during the passenger rush hours, although the locomotive must have fail-safe train protection equipment installed. The freight service under Option 3 is comparable to the base case. None of the services are markedly deteriorated, and some aspects improved for some customers. Furthermore, the transit investment in passing sidings allows more flexibility in operations, reduced time for run-arounds, and faster track speeds. 1.) The NORAC rulebook is referenced because of broad application in Northeast region of U.S.; other standard freight rulebooks do exist and could be used where appropriate. 2.) Grade Crossing Warning Systems at grade crossings are NOT mandated by the FRA or Federal Government. State Law typically establishes the requirements for the type of system installed. The configuration, technology, traffic controls of grade crossings and warning systems are within state and local purview. However, once installed they have to function and be maintained in accordance with FRA 49 CFR Part 234 requirements. The absence or presence of grade crossing warning systems may affect the outcome of the FRA review of a Waiver Petition. For each option it may be necessary to prepare tables, graphics and charts to aid understanding and illustrate the operating characteristics of each option. These would be prepared to support the Major Investment Study and could be adapted for presentation to the FRA in pursuit of a waiver petition. Graphic representation of track occupancy by time of day and route segment for freight and passenger movements Traditional schedule “stringlines” Passenger Train Schedules Passenger Loading per train, time of day, daily trips, standees Track schematics and diagrams for each option Samples of formats and applications of these graphic presentations are included in Task 10 Hypothetical Case Study Report. may not have the flexibility to alter their receiving hours. Reconstruction or reconfiguration of customer sidings may also result. Freight Operations With the introduction of temporal separation, some changes to freight operations are necessary. Identify the volume and mix of traffic moved. Note the changes to times for pick-ups and deliveries, on/off duty times for crews, impacts on train movements, complications for customers. Certain customers Increased speed can be an operating benefit from a transit investment. Under temporal- separation, service markedly deteriorated for some customers. With a separate Freight service on the reconstructed freight track remains unchanged. At any transit/freight track crossings or diamonds, the freight train conductor must contact the transit dispatcher to request permission to cross. Rebuilt track can be built to a higher class in order to raise speeds if desired. freight train to complete the interchange and return more quickly. The chance of “trapping” freight equipment may be minimized. With concurrent shared-track, greater latitude to design freight services is available. The freight local no longer has to work in the exclusive freight window. The on-duty time can be chosen to suit the business. Freight moves can be scheduled to minimize conflict with the passenger traffic. The improved line speeds allow the The freight service operation remains basically the same as Option 3. With shared double-track available, there is much more track for recovery from a disrupted schedule or unexpected events. The double-track affords maximum flexibility to the freight and transit operation to change their shared service plan to provide best service to their customers and constituencies. The freight service is comparable to the base case, but can operate faster, more reliably, and more flexibly.

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TRB’s Transit Cooperative Research Program (TCRP) Report 130: Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner’s Guide examines a business case for the shared use of non-Federal Railroad Administration-compliant public transit rail vehicles (e.g., light rail vehicles) with freight operations and highlights a business model for such shared-use operations. The report also explores potential advantages and disadvantages of shared-use operations and the issues and barriers that can arise in the course of implementation.

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