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

OCR for page 107
108 Shared Use of Railroad Infrastructure with Noncompliant Public Transit Rail Vehicles: A Practitioner's Guide Option 1 2 3 4 Operating Regime Strict Temporal Spatial Separation Concurrent Single Track Concurrent Double Separation Track Infrastructure All signal and communication Freight trains will not operate In essence, when one track systems, track and structures during the passenger peak segment is blocked out to serve are designed, constructed periods. During the off-peak a freight customer, the inspected and maintained to period, freight trains will serve passenger service `sees' an FRA standards. NORAC (see customers en-route, using the additional `single track' section. note 1) operating rules are used sidings to allow half-hourly These constraints impact for all freight and passenger passenger services to `get by' as passenger scheduling, but not as movements. Track is appropriate. severely as it does with single maintained to FRA Class III. track. Grade crossing warning systems should be upgraded to MUTCD standards and be equipped with flashers, bells, and gates. Low-volume or private crossings can be protected by flashers and bells if authorized by State (see note 2). Passenger Identify operations via track The information requirements The information requirements The information requirements of Operations & shared with the freight carrier of Option 1 apply. Along side of Option 1 apply. Option 1 apply. The light rail and the distance traveled over the freight track there is now a The light rail passenger service passenger service differs from Timetable shared-track. Note the time of dedicated transit track. It is differs from Option 1 by having Option 1 by having extended passenger service operations, i.e. primarily single track with two extended service hours earlier service hours earlier in the hours each weekday from start passing sidings to provide for in the morning and later into morning and later into the night. to finish. Describe the bi-directional passenger the night. The passenger The passenger service can temporally separated shared- operations. service can operate 20 hours operate 20 hours each weekday track, e.g., is it primarily single The light rail passenger service each weekday from 5am to 1am from 5am to 1am the next track with any passing sidings differs from Option 1 by having the next morning if it wishes. morningif it wishes. Weekend to provide for bi-directional extended service hours earlier Weekend services can span the services can span the same hours passenger operations. Prepare a in the morning and later into same hours but may have but may have longer headways. train schedule. Typically a the night. The passenger longer headways. As an example, service can service may operate at 15 service can operate 20 hours As an example, service can operate with 15 minute minute headways during the each weekday from 5am to 1am operate with 15 minute headways during the peak daily peak service hours and 30 the next morning. Weekend headways during the peak service hours and 30 minute minute headways during the services can span the same service hours and 30 minute headways during the off peak, off-peak. This provides the total hours but may have longer headways during the off peak, except at late nights when the daily weekday trips in each headways. As an example, except at late nights when the headway is hourly. direction, and peak hour trips. service can operate with 15 headway is hourly. This will establish the number minute headways during the of trains in operation during peak service hours and 30 peak and off-peak service. minute headways during the off peak, except at late nights when the headway is hourly. Passenger Identify the heaviest ridership The information requirements The information requirements The information requirements Distribution period in the shared-track area for Option 1 apply. However, for Option 1 apply. The for Option 1 apply. Passenger on any single train during the ridership for Option 2 captures assumption for rider distribution for Option 4 is the typical service day. Establish additional early morning and distribution for Option 3 same as Option 2. Therefore the any train meets during the late night riders. Overall remains the same as Option 2, ridership calculations will vary. rush-hour. Estimate ridership passenger mobility is increased since the service headway and A full major investment analysis during the midday off-peak with ridership above temporal the span of service remains would determine whether the period by time of day, segment separation because of the unchanged. Therefore the incremental benefit of and direction. Calculation of extended hours. Therefore the ridership calculations will vary. double-track justifies the the passenger loading of trains ridership calculations will vary. incremental cost of its is a key input to the risk construction. 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.

OCR for page 107
Shared-Track Configuration and Operational Alternatives 109 Option 1 2 3 4 Operating Regime Strict Temporal Spatial Separation Concurrent Single Track Concurrent Double Separation Track Freight With the introduction of Freight service on the With concurrent shared-track, The freight service operation Operations temporal separation, some reconstructed freight track greater latitude to design remains basically the same as changes to freight operations remains unchanged. At any freight services is available. Option 3. With shared are necessary. Identify the transit/freight track crossings The freight local no longer has double-track available, there is volume and mix of traffic or diamonds, the freight train to work in the exclusive freight much more track for recovery moved. Note the changes to conductor must contact the window. The on-duty time can from a disrupted schedule or times for pick-ups and transit dispatcher to request be chosen to suit the business. unexpected events. The deliveries, on/off duty times permission to cross. Rebuilt Freight moves can be scheduled double-track affords maximum for crews, impacts on train track can be built to a higher to minimize conflict with the flexibility to the freight and movements, complications for class in order to raise speeds if passenger traffic. The transit operation to change their customers. Certain customers desired. improved line speeds allow the shared service plan to provide may not have the flexibility to Increased speed can be an freight train to complete the best service to their customers alter their receiving hours. operating benefit from a transit interchange and return more and constituencies. The freight Reconstruction or investment. Under temporal- quickly. The chance of service is comparable to the base reconfiguration of customer separation, service markedly "trapping" freight equipment case, but can operate faster, sidings may also result. deteriorated for some may be minimized. more reliably, and more flexibly. customers. With a separate system arrangement, few The fully concurrent track additional freight benefits are sharing affords much more accrued (over the "null" flexibility to the freight carrier. condition). Both the good and If the traffic pattern should bad aspects of the status quo change, then freight train starts are maintained. 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.