April 24, 2024

Automatic Platform Screen Doors: A Safety Feature in Metro Systems

Automatic platform screen doors (APSDs) have become a common sight on metro and subway platforms globally. These full-height transparent doors installed at the platform edge serve the purpose of separating the platform area from train tracks for increased safety of passengers. Let us take a detailed look at how APSDs work and the benefits they provide through various headings and paragraphs.

Working of APSDs
APSDs work in synchronization with arrival and departure of trains. When a train approaches the station, sensors installed on the tracks detect it and signal the platform doors to open. Passengers are then able to board and alight through the open doors. Special sensorsfitted near the doors ensure they close only after the last passenger has cleared the doorway.
APSDs have sliding doors arranged at regular intervals along the platform edge. The doors remain closed when trains are not present and open up section-wise as the train pulls up alongside them for boarding. This controlled opening-closing mechanism prevents any accidental falls onto the tracks.

Safety Benefits
One of the key benefits of APSDs is enhanced safety for passengers by completely segregating the platform area from the tracks. This prevents any accidental falls or pushes onto the tracks which sometimes prove fatal. According to statistics, APSDs can reduce such accidents by around 30-40% every year. They also protect against petty crimes like pickpocketing often reported in crowded stations.

Additional safety features like infrared sensors ensure the doors do not close as long as any part of a passenger’s body is detected near the doorway. This prevents accidents that can occur due to unaware passengers suddenly getting stuck between closing doors. APSDs also alert passengers visually and audibly to not board or alight when doors are closing.

Apart from passengers, APSDs provide enhanced safety for railway staff as well by preventing any direct access to tracks. This is crucial during maintenance works when staff need to access tracks. The screen doors act as a continuous physical barrier affording complete protection from oncoming trains.

Greater Train Docking Accuracy
APSDs facilitate more accurate docking of trains alongside platforms. Special sensorsdetect the exact position of a stopping train and accordingly control door openings for each coach separately. This allows level boarding and alighting significantly reducing boarding time. Precision control of door openings with the train placement prevents any gaps that can cause accidents.

APSD Benefits in Metro Systems
The benefits of APSDs are even more pronounced in busy metro systems with high passenger volumes and frequency of trains. Absence of physical barriers in conventional stations poses serious safety risks during peak hours.APSDs make crowded metro stations much safer by streamlining passenger movements and barring any unauthorized track access. This is crucial formetros that handle over 5 million passengers daily with less than a minute of halting time at each station.

Several Metro networks like Singapore, Hong Kong, Shanghai credit APSDs for smoother operations handling lakhs of commuters safely and swiftly every day.Station dwell times have reduced considerably allowing more trains to be scheduled. Importantly, APSDs elevatethe perception of safety for passengers in metro stations 24×7. This encourages greater ridership over private vehicles supporting urban public transport growth.

Cost Effectiveness
Initial Capital costs for installing full-length APSDs across network stations are admittedly on the higher side, ranging anywhere between $300,000 to $500,000 per station. However, analysing their long-term benefits, this investment pays off through increased revenues from ridership growth and savings from prevented fatal accidents. The total cost of APSD installation gets covered within 4-5 years of operations through such financial returns. Thereafter, only maintenance costs are involved making APSDs a highly cost-effective investment.

Future of APSDs
More and newer metro systems are adopting APSDs proactively considering their irreplaceable safety features and ability to efficiently handle high capacity operational requirements of the future. Technologies like platform edge doors and various types of half-height screen doors for low-footfall stations are also being tested. It is clear that APSDs will be an integral part of metro systems globally to uphold the highest safety standards for public mass transit.

In conclusion, Automatic platform screen doors have revolutionized metro transit safety through synchronized operation with trains. They provide multiple advantages over open access platforms from enhanced passenger protection to facilitating optimal operations. With the important role they play in ensuring incident-free travel for millions daily, APSDs are fast becoming a benchmarksafety feature identifying world-class metro systems.


  1. Source: Coherent Market Insights, Public sources, Desk research
  2. We have leveraged AI tools to mine information and compile it