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.
17 C H A P T E R 3 Introduction This chapter provides a summary of the incident data analysis that was done as part of the research for this manual. It also describes the railroad hazard analysis process and a protocol used in Japan to study platform safety. The chapter concludes with a summary of gap incident reduction program data from three commuter rail agencies. The incident characteristics showed the following trends: ⢠General slips and falls on the platform or within the vehicle tend to be far more common than platform/guideway or platform/vehicle interface incidents. ⢠The most common injury involved falling while boarding or alighting trains. ⢠Incidents involving passengers getting caught in closing doors were common and should be investigated further, because this type of incident could lead to more serious injuries. ⢠All heavy rail transit agencies interviewed reported attempted and successful suicides. ⢠Light rail and streetcar transit agencies reported incidents of people crossing the guideway or sitting on the platform edge. Incident Characteristics Data Collection The incident data collection included workshops, telephone and face-to-face interviews, informal and formal site visits, and web surveys. In addition to contacting stakeholders, the research team examined the FTAâs NTD and FRA safety reports for incident data. There is a dif- ference between FTA and FRA reporting requirements, particularly for intentional trespassing and suicides (46). Many of the project stakeholders recommend more consistency in reporting intentional trespasses and suicides on all rail transit modes. Only one U.S. transit agency provided sufficient platform/guideway and platform/vehicle interface incident data to the research team for use in basic statistical analysis. For other rail transit systems that provided incident data, the team was able to compile the data and look for general trends. The discussions with the transit agencies and analysis of the data indicated that the data analysis needed to be separated by mode: heavy rail, commuter rail, light rail, and streetcar. In addition, the analysis also showed that platform height was a key factor for platform/guideway and platform/vehicle interface incidents. The key incidents under consideration are related to (a) gap and non-gap incidents and (b) boarding and alighting incidents. Platform/Guideway and Platform/Vehicle Interface Incident Characteristics and Rail Safety Programs
18 Manual to Improve Rail Transit Safety at Platform/Vehicle and Platform/Guideway Interfaces Gap- and Non-Gap-Related Safety Incidents One very important distinction with platform/guideway and platform/vehicle interface inci- dent injuries is the difference between gap- and non-gap-related incidents. In general, non- gap-related injuries are far more common on most rail transit systems. For example, only about 25% of the total injuries from 2005 through 2008 on New Jersey Transit actually involved the gap. The remaining injuries involved other factors such as (a) falling onto the tracks when no train was present and (b) slips, trips, or falls around the platform (5). Boarding and Alighting A report published in the United Kingdom (UK) by the Rail Safety and Standards Board (RSSB) makes a distinction between gap-related injuries and non-gap-related injuries. The study specifically divided the data between boarding and alighting incidents versus non-boarding and non-alighting incidents. Non-boarding and non-alighting injuries occur primarily when a passenger is struck by a train entering or leaving a station or result from a fall from the plat- form when no train is present. Throughout the report there are statistics given for both injury categories. In general, based on the data collected there are many more fatalities that occur with non- boarding and non-alighting incidents compared with boarding and alighting incidents. How- ever, there is a higher percentage of fatalities and injuries for boarding and alighting incidents (12%) than for non-boarding and non-alighting incidents (8%) (17). Transit agencies are interested in the difference in risk between boarding and alighting at a rail transit station. A study performed in 2008 by Winnie Daamen, Yu-Chen Lee, and Paul Wiggenraad at Delft University of Technology in the Netherlands suggests that boarding and alighting behaviors depend on characteristics of both the station and the vehicle. The study looked at factors that affect both boarding and alighting times. Alighting headways were shown to be shorter than boarding headways. This is attributed to the queuing patterns near doors, gap size, and presence of luggage (4). Faster alighting times may contribute to the higher percentage of alighting injuriesâ52% of overall injuries reported by the RSSB (17). The study suggested that the faster alighting time contributes to less control and results in more incidents. The study also states that alighting incidents account for more than twice the injury severity potential than boarding incidents. Two possible reasons for this involved falling a greater distance from the train to the platform and having nothing to grab on to outside the train to regain balance (17). In contrast to the Delft study, the New Jersey Transit study found that 66% of all the injuries occurred during the boarding phase rather than the alighting phase (5). Correlation Factors Between Incidents and Interface Characteristics The data analysis and interviews indicate that heavy rail transit has more reported platform/ guideway and platform/vehicle incidents than light rail or streetcar transit. Incident data related to commuter rail operations were not available; however, a summary of the reduction in gap incidents is reported at the end of this chapter. Rail Safety Programs Two railroad hazard analysis processes are identified: the U.S. FRA hazard analysis process and the analytical hierarchy process used in Japan to assess station safety.
Platform/Guideway and Platform/Vehicle Interface Incident Characteristics and Rail Safety Programs 19 FRA Hazard Analysis Process The FRA strongly recommends that passenger railroads work to develop a hazard analysis plan as part of their hazard management process. The plan should ensure that all potential haz- ards are identified, inventoried, analyzed, and then mitigated at the earliest possible opportunity. According to the detailed appendix that was included in the FRA Approach to Managing Gap Safety, there are four main categories to consider for the hazard analysis: people, procedures, equipment/facilities, and environment (9). For a hazard management plan to be effective, it should be created during the design phase for a new transit system and be constantly updated for new and existing systems. A regular review of safety concerns should be scheduled within the plan and should be conducted whenever a gap-related incident occurs. In addition, there should be a review of current mitigation measures at regular intervals. Hazard Identification Process The hazard identification process involves studying all the factors that could result in a pas- senger injury at platform/guideway and platform/vehicle interfaces. These range from passenger characteristics to vehicle and track features. The identified hazards are then assigned a criticality level. The scale ranges from 1 through 4: a 1 is a catastrophic outcomeâdeath, shutdown of system, or severe environmental impact; a 4 is less than minor injury, minimal system damage, or inconsequential environmental impact. The next step examines the potential level of frequency for the identified hazards. This scale uses letters A through E: an A is defined as an event that is likely to occur frequently (once per week); an E is a very unlikely or improbable event (less than once every 10 years). A risk matrix is created from these two metrics to assess each identified hazard. An example that the FRA used in the report is illustrated in Table 3.1. This matrix paired with the suggested actions shown in Table 3.2 can then be used to determine the level of action for each hazard. A mitigation strategy that aims to reduce the severity or the frequency of incident occurrences is then developed. The hazard is re-evaluated with the risk matrix and the suggested action to determine if a satisfac- tory improvement was made. This process generally involves creating a worksheet that can be referenced to determine the effectiveness of different approaches (9). Table 3.1. Risk matrix for hazard analysis (9). Frequency of Occurrence Hazard Categories I Catastrophic II Critical III Marginal IV Negligible A: Frequent 1A 2A 3A 4A B: Probable 1B 2B 3B 4B C: Occasional 1C 2C 3C 4C D: Remote 1D 2D 3D 4D E: Improbable 1E 2E 3E 4E Table 3.2. Suggested actions for identified hazards (9). Risk Matrix Hazard Category Suggested Action 1A, 1B, 1C, 2A, 2B, 3A Unacceptable, eliminate hazard 1D, 2C, 2D, 3B, 3C, 4A, 4B Undesirable, upper management decision to accept or reject risk 1E, 2E, 3D, 3E Acceptable with management review 4C, 4D, 4E Acceptable without review
20 Manual to Improve Rail Transit Safety at Platform/Vehicle and Platform/Guideway Interfaces Japan Study: Analytical Hierarchy Process The case study involving platform safety of railroads in Japan numerically modeled safety to allow risk assessment comparison between stations. The primary goals were to identify specific safety weaknesses at stations and evaluate the effects of potential mitigation strategies. Initially an extensive list of concepts relating to station safety was created. From that overall list, evalu- ation factors were selected for the model that could be quantifiable and were thought to have a significant impact on station safety. These factors were then categorized into four groups: plat- form structure, passenger flow, train operation, and passenger profile. The Analytical Hierarchy Process was used to evaluate the individual factors to determine both major and minor factors that contributed to platform safety. Comprehensive safety scores were developed for a total of 28 platforms at 10 different stations belonging to 7 different railroad com- panies in Tokyo. These results allowed researchers to determine which aspects were most critical in terms of safety hazards at specific platforms. Another interesting feature of the model was the ability to predict impacts to safety based on the manipulation of a given factor. For example, if the overall platform area was increased it would be possible to measure how much safer that improvement would make the platform. This tool could be useful to both researchers and railroad operators (24). Evaluating the Success of Treatment Strategies It is important to establish a method for evaluating the success of treatment or program strat- egies from both a technical and an operational perspective. Specifically, this involves record- ing the number of platform/guideway and platform/vehicle interface incidents before and after the implementation of a treatment strategy or program. If the treatment strategy or program is implemented at a specific station, special consideration should be given to recording incident data at that location. One of the major challenges often associated with recording incident data at a given station is the frequency of occurrence. Platform/guideway and platform/vehicle interface incidents do not occur as frequently as many other types of incidents on either a stationwide or a systemwide basis. Operational changes are often systemwide treatments and keeping track of the overall number of platform/guideway and platform/vehicle interface incidents would provide insight into their effectiveness. Figure 3.1 shows a graph of the reduction in platform/guideway and platform/ Figure 3.1. Chart showing a general trend of a reduction in the number of incidents from 2007 through 2014. 0 50 100 150 200 2007 2008 2009 2010 2011 2012 2013 2014 N um be r o f I nc id en ts Years Gap-Related Incident ReducÂon from 2007 through 2014 LIRR New Jersey Metro-North
Platform/Guideway and Platform/Vehicle Interface Incident Characteristics and Rail Safety Programs 21 vehicle interface incidents on the LIRR, New Jersey Transit, and Metro-North commuter railroads in the United States from 2007 through 2014. Table 3.3 contains the qualitative data supplied by the three commuter railroads. There were reductions in the number of platform/guideway and platform/vehicle interface incidents resulting from multiple treatment strategies and programs undertaken by the rail transit agencies to improve safety. Transit operators in Charlotte, North Carolina; and San Diego, California; also reported a reduction in incidents as a result of treatment strategies and programs at the platform/guideway and platform/vehicle interfaces. Table 3.3. Vehicle gap incidents from 2007 through 2014 for three commuter railroads.
