Metropolitan Transportation Authority One Gateway Plaza 213.922.2000 Tel Los Angeles, CA 90012-2952 metro. net Metro

August 29, 2012

TO: Board of Directors

THROUGH: Arthur T. Leahy ~f~ Chief Executive offocel •' •.. FROM: Krishniah N. Murthy ~v· Executive Director, Transit Project Delivery

SUBJECT: Platform Screen Door (PSD) System Report

ISSUE

Use of Platform Screen Door (PSD) system for Metrorail Stations

DISCUSSION

This brief report is in response to an inquiry received from a board office concerning the use of Platform Screen Doors (PSDs) on our rail system.

Platform Screen Doors have been implemented in transit systems for the following reasons: 1) for automated operations or driverless systems as in most of the airport people movers in the world; 2) specific transit lines where the very high ridership and short operational headway requirements require a full automated operation ( and ); and 3) to have air conditioned stations ().

Metro has previously considered use of the PSDs but has found that the ridership and operational requirements of our Metrorail system would not justify the large investment in such a system. Further, Metro stations are not air conditioned thereby negating one of the apparent benefits of PSDs; in fact, airflow in our stations depends on the piston action of which PSDs would remove from station platforms. The attached summary report "Platform/ Protection Systems Report" was issued in October 2009 by the International Association of Public Transport (U ITP), the international network of public transportation authorities and operators. It compares several protection devices to detect or prevent passengers from falling into the track and concludes that most operators consider the installation of PSDs as normally associated with fully automatic operations. None of the lines operated by Metro have the capability of fully automatic operation. Exceptionally a few agencies, mostly outside the USA, have installed platform doors for specific lines where the capacity requirements required a short operational headway of 90 seconds or less, resulting in a full automation of the line. This is the case in Paris Metro Line 1 and Line 13; Barcelona; 's ; and 3 lines in .

There is no precedent for PSDs being installed in any major U.S. rail transit station in operation today.

The UITP report also looks at PSDs from a safety perspective. While the implementation of PSDs offers benefits, they are not immediately realizable because of the time frame involved in implementing the PSDs on an existing system. Instead, Metro has already begun implementing alternative systems such as fiber-optic based intrusion detection. We are evaluating video based analytics to detect persons or objects that may intrude into the right-of-way and alert control center staff who can intervene and take immediate actions. In the near future we also plan on testing and evaluating similar systems that will alert an approaching operator, by providing an alarm in the train cab, when an intrusion occurs on the right-of-way.

Staff's evaluation of the installation of PSDs has included the significant costs to retrofit existing stations and include PSDs in new stations, life-cycle operational and maintenance costs, possible legal claims when doors malfunction, additional ventilation to supplement lack of piston action air, and additional costs for enhanced train control and interlocking system functionality to work with PSD operation.

NEXT STEPS

Staff does not recommend any further studies on this issue.

Attachment: International Association of Public Transport Report (UITP)

Platform Edge Door (PED) System Report 2 ln ttmationilll Assonttion of Pubhc Tra nsport Un on lnternalfonale des Tr.anspons Publics. lntematkm.\ler Verband fur oHtontllcheJ Verkehnwes.n Unl6n International de .porte PU blico

JUN E 2011 A UITP in formation sheet Core Brief

Platform/Track Protection Systems

Introduction

The purpose of this study on Platform/ Track Optimising the air conditioning sy stem, Protection systems (PTP systems) was to un­ delimiting air circulation, reducing energy derstand the practice of deploying dev ices for consumption. platform/track protection in metro systems Twelve networks responded to the survey: TMB and identify the technical, operational and fi ­ Barcelona, STIB Brussels, Metrorex Bucharest, MTR & KCRC Hong Kong, TL Lausanne, Metro­ nancial considerations when deploying these politano de Li sboa, , NYCT devices. To this end, the Electrical Installations New York, RATP Paris, LTA Singapore and Metro and Safety Systems Metro Subcommittee con­ Warszawskie. This Core Brief presents the con­ ducted a survey in order to assess and com­ solidated results of the survey; the full detailed pare different PTP systems with respect to: study is available to UITP members in Mobi+. • Ensuring passengers' protection; Platform/track protection Preventing intrusions onto the track, systems limiting the number of , protecting against pollution, reducing the occurrence Survey results show that 58% of respondent networks deploy Platform Screen Doors (PS Os ) of fire in tunnels; [this is inclusive of ful l-height and half-height • Improving traffic flow, allowing trains to PSDs and Automatic Platform Gates (APGs)]. enter platforms at a higher speed; PSDs are the single dominant type o f system • Improving operational Quality of Service; used for platform/ track protection. However, • Making better use of the available platform some operators hav e tried o r are considering areas; the use of alternative solutions.

june2011 Benchmarking technologies varies with the pressure applied to it. However, this device is often inappropriate for existing sta­ and applications tions due to the configuration of the tracks, dirty environment and cluttering of the rails. Video Laser scanner The principle behind this technology is based on comparing successive pictures, or the current pic­ A laser distance meter measures the total travel ture and a reference picture. Many automatic in­ time of a laser light pulse between an emitter, cident detection systems relying on this technol­ an object in the environment and a receiver. A ogy are already in use for roads. The algorithms laser scanner takes a set of measurements in ac­ used depend on the type of detection required. cordance with the required resolution with vari­ None of the existing applications are safety ous compositions of angular positions and dis­ critical, although some of them considerably im­ tances. A rotating mirror causes the laser light prove overall safety as well as the perception of to revolve at the rate of 78 cycles per second. it. The limitation of this technology is related to The resolution of the system depends on the dis­ its excessive sensitivity to ambient luminosity tance between the object and the laser. Although and contrast, and to climatic conditions. the technology is sensitive to extreme climatic The intelligent video system (IVS) technology, some­ conditions and to the colour of the object, ap­ times referred to as a behavioural video system, is propriate dimensioning (e.g. four units per plat­ one of the most promising emerging technologies. form) can free the system of these constraints. One of the reasons why IVS is regarded as so prom­ ising is that it can be configured to detect a variety Active radar beam of real-world anomalies. Unlike traditional video de­ The technology of an active radar beam system is tection systems, these systems can be programmed sim ilar to that of the infrared beam but operates in so that alarms are not triggered unless specific be­ the 25GHz-frequency spectrum. Its main advantage havioural patterns are exhibited. This technology is that it is insensitive to interception of the signal can also be applied to PTP in railway networks. by newspapers, plastic bags, etc. It is sensitive to Active infrared beam the mass and density of objects, which makes it ap­ propriate for the detection of intrusions. Sensitivity This system is derived from a device developed for depends on the spacing between beams and on the automatic-start escalators. It detects the on and off chosen threshold (adjustable threshold). states of a modulated infrared beam transmitted perpendicularly to the axis of the tracks below the Platform Screen Doors (PSD) level of the platforms. The combination of transmit­ PSD is the most widely used PTP system. It cov­ ting and receiving diodes ensures a high enough ers more needs than the other systems: prevent­ level of security, as all intrusions prevent the signal ing falls onto tracks (not merely detecting them); from reaching the receiving diode. The system is preventing heat exchange between platform nevertheless vulnerable to false alarms, caused in and tracks; allowing trains to enter stations at a particular by free newspapers, plastic bags, etc. hi gher speed; etc. Two types are in use: the full ­ Weight sensors height PSDs and the half-height PSDs. The lat­ ter have the advantage of being lighter and less Weight sensors use pressure-sens1t1ve mats ar­ onerous with respect to civil engineering but ranged on the tracks and on the platform edge their disadvantage is that it is possible to jump along the whole length of the platform. Applying over them. They also do not provide thermal or pressure on the mat triggers an alarm. Detection sound insulation, which some operators require. is based on the variation of the electri c capacity of While PSD is the most expensive of the various the mats. These mats are made up of two metallic systems used for platform/track protection, it plates that make a capacito r, whose capacitance also offers the highest level of safety.

2 June 20ll Choice of PTP systems and PSDs formance and cost. The choice, therefore, has to be made on a case -by-case basis. The table bel ow Ensuring the safety of the tracks on driverless also illustrates a possible method of as sessment. lines is essential, very often for legal reasons. Most operators, in agree ment with their res pec­ PSDs: design and functionalities tive Authority, req uire the installation of a PTP The main design features and functional require­ system or of PSDs on driverless lines. ments for PSDs are as follows: The choice of using PSDs rather than another PTP • Modular des ig n system should be based on identified needs and Provides a barrier for conditioned air and associated constrai nts. The table below sum­ smoke between platform and track marises the constraints and the performance of Automatic operation based on train each type of system. Gi ven these data, operators movements still have to make the choice between inexpen­ • Use of large glass panel to minimise the impact sive and easy-to-implement solutions that only on tracks ide ad vertising offer a few functional it ies, and a multi-purpose • Computerised fault log with door address but expensive solution. • Adj ustable opening and closing force Most operators consider that installing a PTP sys­ • Obstacle detection on closing tem is a prerequisite for fully automatic operations • Manual override operations and, in the majority of case s, PSDs are adopted. • Detection of open doors (when doors should However, the study also shows that there are dif­ be closed) ferent solu tions in place that meet different needs In the above list, 'modular design' and 'manual and also differ in terms of their constrai nts, per- override operations' are two universal desig n Criteria for selecting PTP systems

PTP sy stem Beam Laser Ra dar Video Weight PSD/ APG barrier scanner beam sens ors sen sor Full· Half · h eight height Interferences Snow, rai n, Snow, rain, Null light Heavy snow Wind Wind sun su n Ro lling stock No specific No specific No specific No specific No specific Doors must Doors must interface interface interface interface interface coincide coincide Duration Quick Quickest Quick Quickest Quick Long Medium z 0 location Along t he Different spots Along the Different spots On the tracks On the On the plat form along t he platform on top of the platform platform ~... and between t racks and between tracks ... tracks for tracks for ;: double tra cks double tracks "':!: Impact on No No No No No Yes Yes o perat ions .... Maintenance Not applicable Not applicable Not applicable Not applicable Not applicable Not Not =:;) pit applicable applicable ti Curved Not applicable Not applicable Not applicable Not applicable Not applicable Gap Gap :;) stations bet ween bet ween 1-= train and train and "'ct PSD for PSD for =.... safety safety :!: reasons reasons False Highest High but could Nu ll Medium Null Null Null detection rat e be lowered using specific algorit hm Safety SIL 2 SIL 2 SIL 2 SIL 0 SIL 2 SIL 4 SIL 4 Int egrity Level (Si l) curr ently achieved Cost Low Low Low Lowest Low High Medium

June 2011 features required for all systems. 'Co mputeri sed Installation constraints fault log with door address' is also applicable to all installations except for small install ations The constraints when installing PSDs seem to be a where only the platform address is shown with barrier to the development of PSDs on existing lines an individual fault log. The ' haz­ (retrofit) and, at present, PSDs are mainly required ard detector' is not as common and it is only for new lines. It is also interesting to note that, from required in Hong Kong and Lausa nne. one country to another; there is significant variation Most PSDs are installed for new lines or new ex­ in the interpretation of safety requirements, which tensions. Thi s is due to the difficulties in justifying results in having systems ranging from SIL 0 to SIL the additional cost of retrofitting on a brownfield 4 for apparently similar functions. site. On existing lines, a large part of retrofitting work has to be limited to a very narrow time Conclusion window of no more than 4 non-traffic hours per PSDs, compared with other PTP devices, are more day. Hence, of the 14 lines with PSDs, 10 are new effective in preventing passengers from intrud­ lines or extensions. Experience in retrofitting is ing on railway tracks. However, operators should relatively rare, as only two operators (Hong Kong consider their own specific needs when selecting MTR & Transports Metropolitans de Barce lona) the appropriate PTP system. It is recommended have installed PSDs on their existing lines (three that they go through an assessment process. lines in Hong Kong, one in Barc elona). Based on the experience of operators who have im­ plemented PSDs , it must be noted that train serv­ Comparison before/after ice is interrupted when PSDs do not work properly retrofit of PSDs based on the because PSD operation is interlocked with the train urban lines of MTR service. In the event that a PSD system is chosen, it is recommended that special attention be given to The use of PSDs has a positive effect on opera­ the design of the system. In particular, the design tions and the availability of train service. This is should include the following: supported by the following data from Hong Kong. • Redundancy and fall-back mechanism (e .g. Impact on operations and the After Before manual release of PSD doors); availability of train service retrofit • Fault monitoring system (e. g. alarm indication Pa ssenger fatal acci dents 12 (including suicides) (year 2000) 0 for individual doors); • Safety aspects (e.g. limited door clos ing force, Lost operational time due to 0.75 0 passenger intrusion minutes/day obstacle detection mechanism, etc.). Lost operational t ime due to 0.075 In the event that an operator chooses a PTP system objects falling on t racks 0 minutes/day only providing intrusion detection, additional meas­ Drivers' sick days due to psychologi- 4 days/year ures should be taken to achieve the overall objec­ cal shock after collision with persons (2 005) 0 on tracks tives of preventing intrusions in protected zones and recovering train service following an intrusion.

This is an information sheet of UITP, th e International This Core Brief Association of Public Transport, has over 3,400 members has been prepared UITP Rue Sainte-Marie 6 in 92 countries throughout the world and represents the by the Metro BE· I 080 Brussels interest s of key players in t his sector. Its membership Committee and Belgium includes transport authorities, operators, bot h private specifically t he Tel: +32 2 673 61 00 and public, in all m odes of collective pas senger transport, Electrical Instal- Fax: +32 2 660 l 0 72 and the industry. UITP addresses the economic, tec hnical , lations & Safety [email protected] organisation and management aspec ts of passenge r Systems Subcom- www.uitp.org transport, as well as the development of policy for mittee . mobility and public transport world-wide.

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