7UDQVLW&DSDFLW\DQG4XDOLW\RI6HUYLFH0DQXDO PART 3 RAIL TRANSIT CAPACITY CONTENTS 1. RAIL CAPACITY BASICS ..................................................................................... 3-1 Introduction................................................................................................................. 3-1 Grouping ..................................................................................................................... 3-1 The Basics................................................................................................................... 3-2 Design versus Achievable Capacity ............................................................................ 3-3 Service Headway..................................................................................................... 3-4 Line Capacity .......................................................................................................... 3-5 Train Control Throughput....................................................................................... 3-5 Commuter Rail Throughput .................................................................................... 3-6 Station Dwells ......................................................................................................... 3-6 Train/Car Capacity...................................................................................................... 3-7 Introduction............................................................................................................. 3-7 Car Capacity............................................................................................................ 3-7 Train Capacity......................................................................................................... 3-7 Station Constraints .................................................................................................. 3-8 2. TRAIN CONTROL AND SIGNALING.................................................................. 3-9 Introduction................................................................................................................. 3-9 Fixed-Block Systems................................................................................................... 3-9 Cab Signaling............................................................................................................ 3-10 Moving-Block Signaling Systems ............................................................................. 3-10 Safety Issues.......................................................................................................... 3-11 Hybrid Systems ......................................................................................................... 3-11 Automatic Train Operation ....................................................................................... 3-11 Automatic Train Supervision .................................................................................... 3-12 Fixed-Block Throughput........................................................................................... 3-12 Station Close-In Time ........................................................................................... 3-12 Moving-Block Throughput ................................................................................... 3-16 Turn-Back Throughput.............................................................................................. 3-18 Junction Throughput ................................................................................................. 3-19 Summary ................................................................................................................... 3-21 3. STATION DWELL TIMES ................................................................................... 3-23 Introduction............................................................................................................... 3-23 Dwell Time Components....................................................................................... 3-23 Doorway Flow Rates............................................................................................. 3-25 Estimating Dwell Times........................................................................................ 3-27 4. PASSENGER LOADING LEVELS ...................................................................... 3-29 Introduction............................................................................................................... 3-29 Loading Standards..................................................................................................... 3-29 Space Requirements.................................................................................................. 3-30 Vehicle Specific Calculations ............................................................................... 3-31 Default Method ..................................................................................................... 3-33 Length ....................................................................................................................... 3-33 Loading Diversity...................................................................................................... 3-35 Part 3/RAIL TRANSIT CAPACITY Page 3-i Contents 7UDQVLW&DSDFLW\DQG4XDOLW\RI6HUYLFH0DQXDO 5. OPERATING ISSUES............................................................................................ 3-39 Introduction...............................................................................................................3-39 Operating Margins.....................................................................................................3-39 Estimating Margins ...................................................................................................3-43 Skip-Stop Operation..................................................................................................3-43 Passenger-Actuated Doors ........................................................................................3-44 Other Station Constraints ..........................................................................................3-44 Wheelchair Accommodations....................................................................................3-45 6. GRADE-SEPARATED SYSTEMS CAPACITY.................................................. 3-47 Introduction...............................................................................................................3-47 The Weakest Link .....................................................................................................3-47 Growth and Achievable Capacity..............................................................................3-48 Simple Procedure ..................................................................................................3-48 Complete Procedure ..............................................................................................3-52 7. LIGHT RAIL CAPACITY..................................................................................... 3-63 Introduction...............................................................................................................3-63 Selecting the Weakest Link.......................................................................................3-63 Other Capacity Issues............................................................................................3-63 Single Track ..............................................................................................................3-64 Calculating Single-Track Headway Restrictions ...................................................3-64 Signaled Sections ......................................................................................................3-66 On-street Operation...................................................................................................3-66 Determining On-Street Capacity ...........................................................................3-67 Right-of-Way with Grade Crossings .........................................................................3-68 Signal Pre-emption................................................................................................3-68 Grade Crossings and Station Dwell Times............................................................3-68 Train Length and Station Limitations........................................................................3-69 Street Block Length...............................................................................................3-69 Station Limitations ................................................................................................3-69 Wheelchair Accessibility Effects...............................................................................3-70 Introduction...........................................................................................................3-70 High Platforms ......................................................................................................3-71 Low-Floor Cars .....................................................................................................3-73 Capacity Determination Summary.............................................................................3-74 8. COMMUTER RAIL CAPACITY ......................................................................... 3-77 Introduction...............................................................................................................3-77