Materials developed by K. Watkins, J. LaMondia and C. Brakewood Rail Capacity Unit 3: Measuring & Maximizing Capacity

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Outline Fundamentals Train control and signaling Train operating

Materials developed by K. Watkins, J. LaMondia and C. Brakewood FUNDAMENTALS

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Main operational terms Capacity = how many people and buses can move past given location during given time Speed = how quickly people and buses can move from one location to another Reliability = how well the bus schedule can be maintained

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Sources of Delay

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Dwell Time = Passenger Service Time + Boarding Lost Time + Door Opening and Closing Time

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Line Capacity = Max # trains on track in given time Controlled by: Signaling system Longest dwell time Speed restrictions (curves or hills) Line crossings and merges Terminal station turn back time Shared tracks Light rail in mixed traffic Commuter rail with freight

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Person Capacity = Max # people carried in one direction over section in given time Depends on: Number of trains operated Length of trains Passenger loading standards Variations in passenger demand

Materials developed by K. Watkins, J. LaMondia and C. Brakewood TRAIN CONTROL AND SIGNALING

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Train Control and Signaling Signaling is to safely separate trains from each other Automatic train control stops train if signal ignored Early trains used line-of-sight basis Human element responsible for ¾ of incidents

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Train Control and Signaling Three (or four) types of signaling – Fixed-Block Systems – Cab Signaling – Moving-Block Systems – Hybrid Systems Automatic Train Operation Automatic Train Supervision

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Basic Signal Operation

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Fixed-block Systems Detected by the wheels and axles of a train shorting a low-voltage current inserted into the rails. Rails electrically divided into blocks – Short in stations – Longer between stations Block is simply occupied or not – Two blocks can be occupied simultaneously – Two-aspect (red/green) block system – Two empty blocks must separate trains Braking distance plus safety distance Maximum 24 trains per hour typical Up to 30 trains with shorter block lengths – Requires substantial training to operate

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Cab Signaling Electronic codes inserted into each track circuit detected by an antenna on each train. Code specifies max allowable speed for block Displayed in cab Speed is adjusted according to conditions Some signals remain at interlockings and station approach

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Moving-block Systems Similar to fixed-block system with very small blocks Continuously calculates safe distance ahead of each train and relays appropriate speed, braking, or acceleration rate – Requires continuous two-way communication) Computers that control moving-block signaling system can be on train, at a central control office, dispersed along the wayside, or a combination of these.

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Hybrid Shared track – No moving block possible Overlay systems – Allow unequipped trains

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Capacity vs Speed

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Automatic Train Operation & Supervision Originally automatic acceleration ATO links this to train control – Follows optimum speed closer – Increases line capacity 2 to 4% Simple ATS – Display location on central control board Advanced systems (ATS + ATO) – Algorithms correct lateness – Algorithms perfect performance at merges

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Preferential Treatments Transitways Transit Signal Priority Queue Jumps Curb Extensions

Materials developed by K. Watkins, J. LaMondia and C. Brakewood TRAIN OPERATIONS Another component to increase capacity, speed and reliability is

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Train Operations Operating Margins Speeding up Train Operations System Design – Disabled Trains – Maintenance – Special Events / Crowd Management

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Operating Margins

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Speeding up Train Operations Skip-Stop and Express Operation Fare Payment Station and Platform Design Doorway Flows Wheelchair Accommodations

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Disabled Trains and Maintenance

Materials developed by K. Watkins, J. LaMondia and C. Brakewood Crowd Management

Materials developed by K. Watkins, J. LaMondia and C. Brakewood References All materials for this lecture were taken from: Chapter 8 of the TCRP “Transit Capacity and Quality of Service Manual, 3 rd edition”, Inventor Spot, Japan: Overcrowded from Cradle to Grave, Retrieved on 20 May 2014 from nes_overcrowded_6802