Rail platform safety

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Platform doors and station agents, here seen on the Taipei Metro, are two strategies for improving rail platform safety. Source: Mailer Diablo

Introduction

Public rail transit is one of the safest forms of transportation, but incidents causing injury and even death can still occur. The risk is highest at the platform, where passengers are close to the guideway and have to step from platform to vehicle. These risks are highest with heavy rail operating on significantly elevated tracks. The Transit Cooperative Research Program has created a manual identifying risk factors and recommending treatments to increase rail platform safety.

Factors Affecting Safety

Platform, Track, and Vehicle Factors

Platform safety starts with good platform design. Large, open platforms with few obstructions are ideal. Higher platforms typical of heavy rail are the most dangerous, but low light-rail platforms come with the increased risk of people walking onto the guideway. Platform surface is also important; cracked, uneven, and slippery surfaces can lead to tripping and slipping. The ADA mandates that platforms have a 24-inch tactile buffer at their edges.

There are a couple of track characteristics to keep in mind when assessing safety. Commuter rail often shares a track with freight trains. Because passenger trains are typically narrower than freight trains, there can be a wide horizontal gap that passengers have to maneuver. Curved tracks also create a large gap at parts of the platform. Superelevated (or banked) tracks create vertical gaps that create tripping risks.

The trains themselves also present potential issues. Plug doors and folding doors both require a sizable gap and prevent level boarding. Newer sliding doors help manage these issues. Because the ADA mandates level boarding, some systems with older cars with include some newer ADA-compliant trains in each consist (or group of cars).

Passenger and Human Behavior Factors

The manual identifies several passenger characteristics that seem to put people at a higher risk of injury. Studies have shown riders younger than 16 and older than 50 to have disproportionately high incident rates. Women also appear to have more incidents; while no causal link has been established, some theories center on the fact that women are more likely to be traveling with young children, who can be distracting. Injuries appear to be highest at rush hour when platforms are most crowded.

There are also behaviors that put passengers at increased risk. Intoxicated passengers have significantly higher incident rates, especially in the evenings. Traveling with large luggage can put passengers at danger - both those with the luggage and others around them. While no data exist on cellphone-related incidents on platforms, general studies on phones and distraction suggest that they are probably risky.

Safety Strategies

Improving platform safety can involve modifications to the station or platform, as well as operational changes.

New York City's Union Square station has moving gap fillers to deal with concave tracks. Source: Antonio Rubio

Station-based treatments

Dealing with gaps is particularly important on high platforms. Gap fillers on the platform edge can help manage horizontal gaps. Wooden gap fillers are the cheapest option but aren’t very durable, whereas aluminum versions are extremely durable. Polyethylene provides a compromise between price and longevity, and can be brightly colored to attract passenger attention. For horizontal gaps, partially raised platforms are a standard option.

Curved platforms pose the biggest challenges because of their larger gaps, so they require extended gap fillers or, in some cases, mechanical platform edge extensions. Platforms shared between freight and passenger rail are also tricky; hydraulic gangways or track switchers that bring the train closer to the platform (called gauntlet track) can be used to account for the smaller size of passenger trains.

Outside the US, it is common to use half- or full-height doors on platform edges to increase safety. While half-height doors and fences are better than nothing, full-height doors provide the most benefits. Not only do they fully block people from falling onto the track, but they also keep the track clean of debris, dampen train noise, and make it easier to ventilate and climate control the platform.

In the event that someone does fall onto the tracks, there need to be detection systems in place. Station agents are the first line of defense, but many systems use automated CCTV to monitor tracks. Radiofrequency and laser technology also can detect guideway intrusion. The trick with any system is to get the sensitivity right; failing to detect a person is unacceptable, but frequent false alarms can cause extensive delays.

Vehicle-based treatments

One of the most common vehicle-based solution to platform safety issues is the static door threshold extension, which minimizes the gap. These can be built onto new trains or retrofitted onto legacy systems. Mechanized systems can also be used. Movable vehicle-based gap systems extend from the vehicle to the platform at platform-level. Ramps and bridging plates work similarly, but rest on top of the platform. All of these systems are designed to only activate when the train is stopped. Some trains also have between-car barriers to keep passengers from falling between vehicles or trespassing onto the coupling system.

Operational treatments

One way to deal with the safety hazards posed by curved platforms is zoning off cars and only opening the doors where the gap is smallest. Being careful about where along the platform to stop the train can maximize the number of accessible doors. This zoning system is only used on commuter and intercity rail and requires strong communication to prevent passenger confusion.

Positioning staff members on platforms can increase safety. Personnel can be trained to identify risk factors and guide traffic at busy times. CCTV can be used as a supplemental tool for monitoring track platform conditions.

Outreach

Rider outreach is an important part of platform safety. The London Underground pioneered this field with the “Mind the Gap” campaign, which American agencies have adopted as “Watch the Gap.” Safety information can be printed on tickets, painted onto platforms, or delivered on standalone brochures. In addition to print, outreach can be conducted with audio and visual messaging. Recently, agencies across the world have begun using social media to educate riders on safety risks.

Manual to Improve Rail Transit Safety at Platform/Vehicle and Platform/Guideway Interfaces

The TCRP Manual to Improve Rail Transit Safety at Platform/Vehicle and Platform/Guideway Interfaces is the primary source for the original article.

Solutions for security enhancement

Crystal Alarm - Personal alarm app - Personal alarm system which can send panic alarms to colleagues onboard the same train using the mobile phones. It can also send panic alarms to traffic control. Special safety modes for dangerous work, for example when personell needs to visit the track area. Integrations possible with Transit software for example HASTUS, Trapeze, IVU.

Additional Reading

Federal Railroad Administration. (2007). "Passenger Rail Station Gap Management Guide, FRA Approach to Managing Gap Safety."

This FRA report summarizes national recommendations on increasing safety relating to platform gaps.

Klein, J. (2010). "ADA Requirements for Rail Operators." Federal Transit Administration.

This brief slide deck summarizes ADA requirements for transit, including standard for gap size and level boarding.

Botha, J. L., Neighbour, M. K., & Kaur, S. (2014). "An Approach for Actions to Prevent Suicides on Commuter and Metro Rail Systems in the United States." Mineta Transportation Institute.

While covered in less depth in the manual, suicide prevention is an important aspect of rail safety.