Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
36 Introduction This chapter describes the treatment strategies that improve safety at the platform/guideway interface. Most of the treatment strategies involve the platform infrastructure. However, the last section of the chapter includes track geometry treatments. Strategies and treatments addressed in this chapter include the following: ⢠Platform-based treatments ⢠Platform edge treatments: gap fillers ⢠Vertical gap treatment ⢠Special treatments for curved platforms ⢠Treatments for shared use high height platforms ⢠Electronic systems for guideway intrusion detection ⢠Guideway intrusion prevention ⢠Other platform treatments ⢠Track geometry treatments This chapter highlights treatments observed during two site visits of rail transit agencies in the New York City region and in Southern California. The New York City region rail agencies include NYCT, New Jersey Transit, the Port Authority of New York, LIRR, and AirTrans. The Southern California agencies include Los Angeles Metro (LA Metro), NCTD, and Amtrak. The New York City region examples show treatments that address some of the challenges of legacy rail transit systems and curved track. All the Southern California systems have been in operation fewer than 50 years. The Southern California examples from San Diego are primarily of light rail and streetcar transit operating in the street and at low height level platforms. The LA Metro examples are on high height level platforms. NCTD is an example of a hybrid commuter rail system that operates on shared use track and at high height level platforms. Treatment examples are also included from rail transit agencies in the following cities: Portland, Oregon; Tacoma, Washington; Miami, Florida; Charlotte, North Carolina; Denver, Colorado; Kansas City, Missouri; San Francisco, California; Chicago, Illinois; Washington, DC; Philadelphia, Pennsylvania; Honolulu, Hawaii; and Oakland, California. The Canadian cities that contributed include Vancouver, Toronto, and Ottawa. Platform-Based Treatments Most of the platform-based treatments are used on platforms that are 3 ft or more from the top of rail and are considered high height level platforms. Table 6.1 contains the type of treat- ment and the platform height. These treatments reduce the horizontal and vertical gap between Treatment Strategies to Improve Safety at the Platform/Guideway Interface C h a p t e r 6
Treatment Strategies to Improve Safety at the Platform/Guideway Interface 37 Table 6.1. Platform-based treatments and platform height. Platform-Based Treatments Platform Height High (greater than 36 in. from top of rail) Mini-High (15 to 36 in. from top of rail) Low (8 to 15 in. from top of rail) Platform Edge Treatments: Gap Fillers Wooden Gap Fillers Plastic Polyethylene Extruded Aluminum Rubberized Platform Edge Platform Fixed Gap Boards Vertical Gap Treatment Raised or partially raised platforms Special Treatments for Curved Platforms Static Gap Fillers: Wood, Plastic (Sacrificial Boards) Mechanical Platform Edge Moveable Platform Edge Treatments for Shared Use High Height Platforms Hydraulic Gangways Movable Platforms Gauntlet Track Electronic Systems for Guideway Intrusion Detection Radio Frequency (RF) Curtain Closed-Circuit Television (CCTV) with Advanced Analytics Thermal Imaging Laser Detection Special Cameras Pressure Plate Infrared (IR) Beam Guideway Intrusion Prevention Platform Screen Doors Platform Edge Fences Other Platform Treatments Mode Share Platforms Overhead Platform Lighting Platform Edge Lighting Tactile Edge Treatment Platform-Based Bollards Platform Door Position Locators (CA) Platform-Based Ramps and Bridges
38 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces the platform edge and the train car to prevent passengers from stepping, tripping, or falling into these gaps. The solutions range from wooden boards to sophisticated platform screen doors. The platform- based treatments include treatment of the platform edge, gap fillers, and tactile edge treatments. Platform Edge Treatments: Gap Fillers It is often necessary to install gap fillers at the platform edge on tangent or straight track plat- forms due to construction tolerances or techniques. These are called ârubbing boardsâ by some transit agencies and are used to reduce the horizontal space or gap between the platform edge and the vehicle. These rubbing boards protect both the integrity of the platform edge and the side of the vehicle and are often called a âsacrificialâ platform edge. These gap filling methods must also take into account variations in vehicle height resulting from vehicle and rail wear. The most common materials used are wooden boards, polyethylene, or extruded aluminum. These boards are securely and permanently fastened to the fixed edge of the platform. Wooden Gap Fillers Wooden gap fillers are lower cost per linear foot, but the material weathers and may not be as durable as polyethylene or extruded aluminum. Figure 6.1 shows an example of a wooden edge or running board. This may be an economical solution, but it requires replacement when the wood is damaged or worn out. Plastic Polyethylene Strip Figure 6.2 shows a red plastic polyethylene strip attached to the platform edge. Polyethylene is more expensive than wood but has a longer life. Polyethylene rubbing boards that are used in underground stations have fire retardants added to the material. The contrasting color of the plastic provides an additional high visibility feature to warn passengers of the edge of the Figure 6.1. Wooden platform edge gap filler (14).
treatment Strategies to Improve Safety at the platform/Guideway Interface 39 platform. For example, the LIRR uses red colored polyethylene to increase the color contrast at the platform edge and provide a rubbing surface. Extruded Aluminum Platform Edge Protection LA Metro uses extruded aluminum to provide additional platform edge protection (see Fig- ure 6.3). This material has been in place for over 10 years with no reported wear or maintenance requirements. Figure 6.2. Contrasting colored red stripe along the edge of the platform, LIRR. [Images of LIRR © Metropolitan Transportation Authority. Used with permission.] Figure 6.3. Extruded aluminum platform edge gap filler.
40 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces Rubberized Platform Edge Gap Filler An Australian report reviewed platform/train interface technologies that ranged from patented concepts to installed systems (28). One of these treatments is a rubberized platform edge gap filler that as shown in Figure 6.4. Platform Fixed Gap Boards On existing platforms used by legacy rolling stock, a horizontal gap may exist when new vehicles are used. In this case, fixed boards are attached to the platform and are added only at the expected door positions. This can only be achieved if a train consist always has the same vehicle configura- tion with predetermined or predictable door locations. Boards may be applied to the whole length of the platform; however, this will create other challenges if operations are shared with freight trains. Figure 6.5 shows permanently fixed platform boards installed on the commuter train system in Ottawa that currently operates on exclusive track (i.e., it is no longer used for freight operations). Figure 6.4. Rubberized platform edge gap filler (28). Figure 6.5. Fixed platform board on the OC Transpo light rail system in Ottawa, Canada.
treatment Strategies to Improve Safety at the platform/Guideway Interface 41 Vertical Gap Treatment Raised or Partially Raised Platforms Figure 6.6 shows the platform in the Vauxhall Station of the London Underground that has been partially raised to reduce the vertical gap between the platform and the vehicle. In addition, the overhead sign shown in Figure 6.7 indicates the location of the accessible door. Figure 6.6. Partially raised platform at the London Underground Vauxhall Station. Figure 6.7. Accessible door location marking on raised platform edge and overhead placard showing location of accessible door.
42 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces Special Treatments for Curved Platforms There are a number of special treatments for curved platforms including the following: ⢠Static gap fillers ⢠Mechanical platform edge ⢠Under-platform mechanical gap filler Static Gap Fillers Static gap fillers that are used on curved platforms are wider than those used on tangent plat- forms. The extra wide static gap fillers are used to fill the increased horizontal gap that results from the curved platform and vehicle door locations. They are permanently attached to the platform edge. The most common type of static gap filler for curved platforms is the same as the platform edge material; however, it was observed that wood is often used as a âsacrificial boardâ added to the platform edge, even if the platform edge is polyethylene. Figure 6.8 shows extra wide polyethylene materials at the curve. Mechanical Platform Edge A mechanical platform edge is a section of the platform edge that moves mechanically at the train door location to fill in horizontal gaps that exceed 10 to 12 in. There are markings stenciled on the platform to warn passengers to stand clear of the moving platform. Figure 6.9 contains four photo- graphs: the top left is of the curved platform at NYCTâs 14th StreetâUnion Square station and the remaining three photographs are of the mechanical platform edge at NYCTâs South Ferry station. The old South Ferry station was sharply curved. The new South Ferry station replaced the sharp curve with a very gentle curved alignment (5,200 ft. radius). However, Superstorm Sandy flooded the new station and the old station was brought back into service while repairs are made to the new station. The mechanical platform edge will be âretiredâ when the new South Ferry station is reopened. Figure 6.8. Polyethylene platform edge gap filler with sacrificial edge. [Images of LIRR © Metropolitan Transportation Authority. Used with permission].
treatment Strategies to Improve Safety at the platform/Guideway Interface 43 Figure 6.9. Curved platform (top left) and movable platform edge gap filler (remaining images). [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission]. Under-Platform Mechanical Gap Filler NYCT also uses a mechanical under-platform edge gap filler. This under-platform edge gap device fills in the space between the vehicle and platform to prevent falls down to track level. The under-platform gap filler shown in Figure 6.10 is used on the 42nd Street Shuttle that connects Times Square to Grand Central. It operates on the former Interborough Rapid Transit (IRT) Company Line on tracks that opened for operation in 1904. The mechanical platform edge gap fillers have direct and indirect costs. These technologies must be interlocked with the signal system and require increased maintenance. In addition, failure of these devices will impact station dwell time and overall system operations. Main- tenance requires deactivation of the platform from service, which can be more disruptive
44 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces than static or vehicle-deployed gap fillers that can be maintained without putting a station out of service. Treatments for Shared Use High Height Platforms The most common types of platform-based treatments for platforms gaps on track that is shared between passenger and freight rail operations include hydraulic gangways, movable platforms, and gauntlet track. Hydraulic Gangways Hydraulic gangways are mechanically operated platform extensions that span the wide horizontal gap created by freight car side clearance regulations. A central dispatching center remotely operates the gangway. Access to the platform edge is fenced off with only the gang- way section open for the boarding and lighting passengers. The gangway is the only section that bridges the horizontal gap for access to the passenger train. In compliance with ADA regulations, a standard tactile warning strip is used along the entire width of the gangway. In addition, horizontal detectable bars are placed both on the gangway and set back on the platform to identify door locations for passengers with low vision. These are shown in Fig- ures 6.11 and 6.12. Hydraulic gangways are effective for temporally separated rail traffic, and they have the potential to operate on systems that have interspersed traffic. The effectiveness of the hydraulic gangways is dependent on a number of factors including, but not limited to, the host railroad, number of passenger trains per day, number of freight trains per day, headways between passenger trains and freight trains, and the budget of the transit agency (43). Heavy mixed rail traffic operations complicate train dispatching with respect to ensuring that all the gangways are in the correct posi- tion. In addition, there is a need to ensure in fail-safe modes that the gangway operation is tied into the signal system. Figure 6.10. Gap filler below platform, NYCT. [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission].
treatment Strategies to Improve Safety at the platform/Guideway Interface 45 Movable Platforms Movable platforms have been developed for Amtrak to reduce the horizontal gap between the passenger train and the platform on shared use tracks. A section of the platform moves horizon- tally toward the door area to allow passengers to board. Figure 6.13 shows a picture of a movable platform. Gauntlet Track A gauntlet track is a track-based treatment for shared use high level platforms. A gauntlet track is a parallel track to the main track that is used to bring the rail transit train closer to the platform to reduce horizontal gaps. The gauntlet track runs the length of the platform with two switches for the train to come on and off the main track. A gauntlet track is not a traditional siding track where the passenger train moves to a new track with full track spacing, but rather the switches Figure 6.12. Hydraulic gangway gap filler deployed. Figure 6.11. Hydraulic gangway gap filler retracted (49).
46 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces move the train to an offset track that features one rail between the existing rails and one slightly outside (15). Figure 6.14 shows a picture of the gauntlet track used on the Westside Express Service (WES) commuter rail system in Portland, Oregon. Electronic Systems for Guideway Intrusion Detection Guideway intrusion detection systems are technologies that detect objects moving from the rail transit platform toward or on to the tracks. The technology for the guideway intrusion detec- tion has become more sophisticated and can be far more economical to install and operate than guideway intrusion prevention systems such as platform edge doors. In the United States, there are several demonstration projects funded by the FTA evaluating the effectiveness of new technologies for detecting intrusion onto the guideway. The following technologies are currently being evaluated by U.S. rail transit agencies: ⢠RF curtain ⢠CCTV with advanced video analytics ⢠Thermal imaging ⢠Laser detection system The four technologies use very different approaches to detect intrusion. A key to detection is the level of sensitivity. Once a system has made a detection, a message or alert is sent to central Figure 6.13. Movable platform concept by AMTRAK Rail Vehicle Access Advisory Committee (RVAAC). Figure 6.14. Gauntlet track at a WES commuter rail station in Portland, Oregon.
treatment Strategies to Improve Safety at the platform/Guideway Interface 47 control for an appropriate action. If the detection system is too sensitive it may detect flying papers, incurring false positives and operational delays. If the system is not sensitive enough to detect a person trespassing on the track and guideway, then there may be serious consequences. Each rail transit agency has unique operating characteristics that influence operational proce- dures once a detection has been made. Figures 6.15 through 6.19 show examples of detection systems in rail transit stations. Figure 6.15. 24 GHz RF curtain. [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission]. Figure 6.16. CCTV with advanced video analytics software. [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission].
48 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces Figure 6.17. CCTV advanced video analytics software in operation (21). RF Curtain. The 24 GHz RF curtain that is used to detect intrusion into the guideway is shown in Figure 6.15. CCTV with Advanced Video Analytics. There are several rail transit agencies that use CCTV with advanced video analytics software to detect intrusion. This technology also permits valida- tion through the CCTV camera (see Figure 6.16). Figure 6.17 is a schematic of a CCTV with advanced video analytics. The schematic shows the platform area that the CCTV cameras are scanning. The information from the cameras is sent to a computer for processing and a graphical image with analytics is produced. Thermal Imaging. This technology is rapidly evolving in applications. A thermal imaging camera uses IR radiation to construct images as opposed to a regular camera that uses visible Figure 6.18. Thermal imaging detection system. [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission].
treatment Strategies to Improve Safety at the platform/Guideway Interface 49 light to form an image. Figure 6.18 shows an installation of a thermal imaging detection system in a rail transit station. Laser Detection System. Figure 6.19 shows a sensor for a laser detection system. This technol- ogy detects intrusion and is often paired with CCTVs for verification or validation of an intrusion. Outside the United States, other technologies such as special cameras, pressure plate detection, and IR beam are being used for intrusion detection. Special Cameras. At the Kyobashi train station in Osaka, Japan, 46 specially designed cam- eras have been installed to scan for signs of intoxicated passengers. The cameras look for signs such as passengers staggering or falling asleep on benches, which trigger a response from station attendants (47). Pressure plate detection. The original Expo Line of Skytrain in Vancouver, BC, started rev- enue service in 1986. Skytrain is driverless, is fully automated, and has automatic train control (ATC). Skytrain has two types of guideway intrusion detection systems: (a) the original pressure plate detection system on the Expo line and (b) IR beam sensitive guideway intrusion detection on the newer Millennium and Canada lines. The Expo line has pressure sensitive plates that are located on the tracks at stations. The system detects objects that put pressure on the plate, and then issue an alert to a central control room. Central control then uses CCTV for validation. The system is very effective, but there have been challenges with the level of sensitivity. A dropped alu- minum can or wallet can create false alarms that stop trains and cause service disruptions (2, 25). IR beam. The newer Millennium and Canada linesâ guideway intrusion detection system uses an IR beam detection system at the platform edge and on the track. The main purpose of the detection technology is to prevent an incoming train from hitting a passenger on the tracks. Figure 6.19. Laser detection system. [Images of NYC Subway © Metropolitan Transportation Authority. Used with permission].
50 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces The IR beam detection systems present on the newer lines can detect a passenger moving too close to the platform edge and issue an audio warning of the danger. The second part of the system can detect an object that has fallen on the track. An alert is sent to a central control room when an object is detected and trains cannot enter the station until the foreign object is cleared. Skytrain has extensive camera coverage of all platforms systemwide and dedicated staff in central control to monitor the cameras. Guideway Intrusion Prevention Guideway intrusion prevention systems are technologies located on or above the rail transit platform or guideway that prevent objects and passengers from falling or tripping into the guide- way and onto the train tracks. Guideway intrusion prevention is becoming more common on new rail transit systems that operate under ATC (i.e., without a driver or conductor on board). An early version of ATC technology is the automatic people mover that has been implemented at airports. There are three types of guideway intrusion prevention technologies: ⢠Platform screen doors (full height) ⢠Platform edge doors (half height) ⢠Platform edge fences Platform screen doors, platform edge doors, and platform edge fences at train or subway stations provide a physical barrier between the platform and the train and, therefore, improve passenger safety at the platform/vehicle interface. Platform edge doors are usually required to implement Automatic Train Operation (ATO)/ATC. Because these doors and fences prevent guideway intru- sion, they also prevent the service delays that result from such intrusion. A report on the Paris subway stated that the number of delays caused by passenger guideway intrusion was reduced by 69% after the installation of platform screen doors. Figures 6.20 and 6.21 show full height and half height platform doors. Platform Screen DoorsâFull Height. Full height platform screen doors provide full sepa- ration and can mitigate noise and ventilation problems in below grade stations. The doors have additional benefits including (a) compliance with modern codes such as National Fire Protection Figure 6.20. Full height platform screen doors, Paris, France (PB Bulletin).
treatment Strategies to Improve Safety at the platform/Guideway Interface 51 Association 130, (b) providing climate control, and (c) accommodating faster train headways. Full height platform screen doors or barriers necessitate separate guideway and platform ventila- tion systems thereby creating a smoke and fire barrier for passengers on the platform if there is a fire in the guideway. Underground stations in Singapore have been retrofitted with full height platform edge doors to help improve safety and to reduce the costs of providing air condition- ing on the platforms. The savings from this retrofit are significant and passenger comfort has improved immensely. Platform Edge DoorsâHalf Height. Half height platform edge doors extend up to about 4 ft, with the actual height dependent on the specific system. This configuration represents the most cost-effective way to install platform edge doors and, although there is ventilation between the platform and the guideway, there is not much climate control and train noise suppression is minimal. One potential problem with half height doors is that a passenger could climb up over the wall and enter the guideway. Platform Edge Fences. Platform edge fences are similar to half height platform edge doors. They have an open grill and do not provide any noise suppression or climate control. Managing delay caused by (a) guideway intrusion and (b) boarding and alighting is a key motivation for investing in platform edge doors. It is therefore important to understand the potential effects that installing platform edge doors have on delay on a rail transit line. Skytrain in Vancouver, BC, conducted a delay impact analysis by comparing the delay of platform edge doors with the current guideway intrusion detection system. The study concluded that the potential delay caused by the platform edge doors would be less than half of the delay that occurs with the current intrusion detection technology (8). One major assumption of this comparison between platform edge doors and the current intrusion detection technology was that the platform edge doors would fail at about the same rate as that of the train car doors. In the analysis conducted for Skytrain, it was assumed that the current intrusion detection systems would be removed and thus no delay would be encountered from these systems. The delay study findings suggest that the platform edge doors would reduce delay significantly over the course of an average month (8). Other transit agencies in Asia and France reported that the reduction in delay and station dwell time are the motivation for installing platform edge doors. Similarly, results from instal- lation of half height platform edge doors on Hong Kongâs Mass Transit Railway (MTR) system suggest that service interruptions due to intrusion dropped nearly 70% (2). Figure 6.21. Half height platform doors at Meguro Station, Tokyo, Japan (51).
52 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces Global Experience with Platform Screen and Platform Edge Doors Platform screen and platform edge doors are a relatively new addition to 50 rail transit systems around the world. Platform screen and platform edge doors have been installed in Paris, London, Toronto, and in parts of Asia to maintain physical separation between passengers waiting on the platform and the track. Paris. Platform screen doors were introduced in 1998 on the Métréor (Métro Est-Ouest Rapide) line. This is a fully automated rail transit line and the platform screen doors were intro- duced to prevent accidents and suicides. London. Platform screen doors were introduced on the Jubilee line extension in 1999. London is planning to install platform screen doors on additional lines and use ATO. Toronto. Platform screen doors have been installed at two stations on the new Union Pearson Express train that connects Downtown Toronto with Pearson Airport. The platform screen doors maintain station temperature and provide protection from extreme weather. Bangkok. A report published by Santoso and Mahadthai focuses on platform edge door impacts on platform safety on the Bangkok Mass Transit System. According to the findings, inci- dents that are attributed to platform/guideway interface incidents account for about 38% of the overall fatality risk and of that risk about 9% are attributed to boarding and alighting incidents. The platform edge doors improved safety surrounding the platform/vehicle interface. Taipei. An internal case study completed by the Taipei Rapid Transit Corporation describes the results of previous installations of platform edge doors on various rail transit lines under their jurisdiction. Platform edge door installations shown in Figure 6.22 began in 2005 and have con- tinued periodically since that time. Initially, the doors that were installed were 1.45 m (4.76 ft) tall and 1.8 m (5.91 ft) wide; however, as more stations were equipped with platform edge doors, the heights of the doors have been reduced slightly to 1.4 m (4.59 ft) and the width has increased to 2.1 m (6.89 ft) to increase visibility and passenger flow. Additionally, the doors are equipped with automatic detection sensors that prevent them from closing on passengers and causing inju- ries. Recent successes with the platform edge doors have encouraged the Taipei Rapid Transit Corporation to continue installing the doors at heavily congested stations. The most recent set of installations at 13 additional stations was completed in 2014 (10). Figure 6.22. Half height platform edge doors, Heng Fa Chuen MTR station platform (52).
treatment Strategies to Improve Safety at the platform/Guideway Interface 53 Honolulu. Platform edge doors will be installed at all 21 stations along the new Honolulu Rapid Rail Transit line that will operate under ATC. Both the planners and the community at large recommended the installation of the doors. This is largely due to the system being both elevated and automated. The half height doors will be laminated safety glass and will run along the entire length of each platform. As observed at other systems around the world, installing the doors is significantly cheaper if done during initial construction rather than retrofitting later. The automatic doors will be installed at an estimated cost of $27 million total for all the platforms in the 21 stations (7). In all cases, platform edge gates/doors/barriers are used to prevent service delays that result from guideway intrusion. Other Platform Treatments Other platform treatment strategies that impact the safety at the platform/guideway interface include the following: ⢠Mode shared platforms ⢠Platform edge lighting ⢠Overhead platform lighting ⢠Tactile edge treatment ⢠Platform-based bollards ⢠Platform door position locators ⢠Platform-based ramps and bridges Mode Shared Platforms The design for the new Kansas City Downtown Streetcar system had to meet the challenge of platforms shared by streetcars and buses. The streetcar vehicles selected for this new system have ADA accessible doors in the middle section of the vehicle, and the station platforms were designed to reflect this feature. For example, the platforms have a 14-in. height from top of rail to provide a level boarding section in the middle of the platform that aligns with the ADA accessible doors. At either end of the station, the platform dips down to 7 in. above top of rail or road surface where streetcar and bus passengers step up or down to board or alight the vehicles. One of the primary reasons for this design was to reduce the streetcar stationsâ footprint in the urban environment. According to the design documents, nearly one-half of the station locations had space constrained by obstacles such as parking, loading zones, and driveways. Providing for level and accessible boarding at only the middle two doors reduces the station footprint compared with a traditional platform that allows level boarding at all the doors. The second reason for this configuration is to allow the existing buses in Kansas City to use the stations. This platform style is also used for the Washington, DC, streetcar at select stops (6). In Seattle, the light rail vehicles and buses also share platforms (16). Platform Edge Lighting Platform edge lighting is a permanently installed system of lights at the edge of the rail station platform to highlight the platform edge and alert passengers. Platform edge lighting has been used in limited applications in the United States. In Washington, DC, WMATAâs heavy rail transit system was constructed in the 1980s. In 2007, WMATA embarked on a program to replace the original edge warning lights with light-emitting diode (LED) platform edge lights. The bulb burns
54 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces steady at 50% power, and flashes at 100% power when a train approaches or is at the station. All the new LED lights are red as shown in Figure 6.23. Overhead Platform Lighting Overhead platform lighting is a band of lights installed above the platform edge to increase the visibility of the platform edge for passengers. Figure 6.24 shows two examples of good platform edge lighting: the left image shows the overhead lighting reflected on the marble platform of Figure 6.23. Platform edge lights, WMATA. Figure 6.24. Overhead platform lighting at the World Trade Center station (left) and LIRRâs Atlantic Terminal (right). [Image of LIRR © Metropolitan Transportation Authority. Used with permission].
treatment Strategies to Improve Safety at the platform/Guideway Interface 55 the new World Trade Center station in New York City; the right image shows the continuous overhead platform edge lighting of the LIRRâs Atlantic Terminal. Also visible in Figure 6.24 are the extra rubbing boards on the platform edge of the Atlantic Terminal. Tactile Edge Treatment Tactile edge treatment consists of high color contrasting truncated/linear shapes molded into plastic or platform surfaces at the edge of platforms. The tactile edge treatment is designed to be detectable and identifiable by passengers with visual impairments who use a cane or other means of detecting surface shapes to alert them of the platform edge. The U.S. Department of Justice and the U.S. DOT ADA regulations both require that platform edges not protected by doors, screens, or guards have detectable warnings that are 24 in. wide along the full length of the public use area of the platform. The truncated domes that are used for the detectable warning can cause problems for vehicle-based ramps and bridges. The San Diego Trolley developed a treatment strategy that was approved through the equivalent facilitation pro- cess (41, 42). These tiles are used by other transit agencies including Utah Transit Authority in Salt Lake City and TRIMET in Portland, Oregon. There is a clear space within the truncated domes that allows for the safe deployment of the vehicle ramp. Figure 6.25 shows these tiles. Figure 6.25 also shows a station that is on a curve with a horizontal gap that is bridged by a ramp deployed from the under the door threshold. Deployment of the ramp can only occur when the car doors are closed. Ramp deployment is done upon request by pressing a switch inside or outside of the vehicle. The door must be closed before and after deployment of the ramp. To manage dwell time, most transit systems have the ramp deploy upon request and not automatically. Platform-Based Bollards There are two different approaches to treating between-car intrusions: platform-based or vehicle-based systems. Platform-based bollards are used on systems where the length of the vehicle is consistent and the location of the area where the coupling between the two cars can be predicted. Figure 6.25. Truncated domes with clearance space for vehicle ramp deployment, San Diego, California.
56 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces The space between the cars presents a danger for passengers if they fall or trip from the platform into this space. Incident data analysis showed that there were very few platform/vehicle gap inci- dents on light rail or streetcar transit systems. However, several light rail transit agencies reported that between-car intrusions were a problem. Federal regulations require between-car barriers when the train consist is made up of more than one car. (49 CFR§38.85). Platform-based systems depend on standardized vehicle lengths (18). LA Metro worked with a number of private and public agencies to develop a system that met federal, state, and munici- pal requirements. Other transit agencies across the United States have similar installations. The platform-based bollards are permanently installed metal or plastic posts on the platform. The bol- lards have high color contrast so that people with vision disabilities can see them and they present a barrier that prevents passengers from falling between cars. Figure 6.26 shows platform-based bollards that are designed to reduce between-car intrusions. Platform Door Position Locators The California Public Utilities Commission, which provides state oversight of rail transit, recommends that train door locations be marked for passengers with low vision. Platform door position locators are tactile platform floor treatments that indicate the anticipated location of the train car door. The tactile floor treatment is detectable and helps passengers with low vision identify the door location. San Diego Metropolitan Transit System (MTS) and LA Metro adopted tiles with horizontal bars that are perpendicular to the platform edge to denote boarding locations as shown in Fig- ure 6.27. In addition, San Diego MTS also places signs with both lettering and braille to denote the location and direction of the train for passengers with low vision. Platform-Based Ramps and Bridges Platform-based ramps and bridges are portable lightweight devices that are used in commuter and intercity passenger rail operations to span the gap between the platform and vehicle when there are station staff or conductors on the vehicle. Platform-based ramps and bridges are designed to be placed over horizontal and small vertical gaps to prevent passengers from slipping into these gaps. They are also used to assist passengers using mobility devices, such as walkers, wheelchairs, Figure 6.26. Platform-based between-car barrier.
treatment Strategies to Improve Safety at the platform/Guideway Interface 57 and scooters to board and alight. Transit agencies have serious concerns about the use of portable ramps and bridges in high volume rapid transit application due to the impact of station dwell time and system capacity. Figure 6.28 shows two different types of platform storage for ramp equipment. Track Geometry Treatments Treatments for improving track geometry may involve straightening the track, realigning the track, and stabilizing the track geometry. Straightening or realigning the track to remove curved track is a major capital project that often involves the complete redesign and reconstruction of platforms and stations. Straight track improves passenger access to the train by providing a constant horizontal distance between the platform and all train cars. Curved track in stations not only introduces increased horizontal gaps, but curved track is also subject to increased stress that can cause the track geometry to change. Track stabilization is used to maintain track geometry. This can include the use of vertical anchors attached to ties that are buried into the ballast or, as shown in Figure 6.29, wooden ties placed between the platform structure and the concrete ties. Both methods can be used to maintain proper spacing and track geometry in curved track stations. Slab track, direct fixation track, or ties embedded in concrete are also much less prone to lateral shifting as long as the integrity of the rails and fasteners is ensured. Some rail transit agencies use geometry measurement vehicles to ensure that track spacing and location are accurate. Figure 6.27. Door location tactile platform markings used in California.
58 Manual to Improve rail transit Safety at platform/Vehicle and platform/Guideway Interfaces Figure 6.28. Wheelchair ramp stored on the platform (left) and bridge plate stored on the platform (right). [Images of Metro-North © Metropolitan Transportation Authority. Used with permission]. Figure 6.29. Track geometry stabilization.
